ERC FUNDED PROJECTS

How does the inside of the proton look like? What generates its spin?
3DSPIN will deliver essential information to answer these questions at the frontier of subnuclear physics. At present, we have detailed maps of the distribution of quarks and gluons in the nucleon in 1D (as a function of their momentum in a single direction). We also know that quark spins account for only about 1/3 of the spin of the nucleon. 3DSPIN will lead the way into a new stage of nucleon mapping, explore the distribution of quarks in full 3D momentum space and obtain unprecedented information on orbital angular momentum. Goals 1. extract from experimental data the 3D distribution of quarks (in momentum space), as described by Transverse-Momentum Distributions (TMDs); 2. obtain from TMDs information on quark Orbital Angular Momentum (OAM). Methodology 3DSPIN will implement state-of-the-art fitting procedures to analyze relevant experimental data and extract quark TMDs, similarly to global fits of standard parton distribution functions. Information about quark angular momentum will be obtained through assumptions based on theoretical considerations. The next five years represent an ideal time window to accomplish our goals, thanks to the wealth of expected data from deep-inelastic scattering experiments (COMPASS, Jefferson Lab), hadronic colliders (Fermilab, BNL, LHC), and electron-positron colliders (BELLE, BABAR). The PI has a strong reputation in this field. The group will operate in partnership with the Italian National Institute of Nuclear Physics and in close interaction with leading experts and experimental collaborations worldwide. Impact Mapping the 3D structure of chemical compounds has revolutionized chemistry. Similarly, mapping the 3D structure of the nucleon will have a deep impact on our understanding of the fundamental constituents of matter. We will open new perspectives on the dynamics of quarks and gluons and sharpen our view of high-energy processes involving nucleons.

1 509 000 €

Start date: 2015-07-01, End date: 2020-12-31

State-of-the-art microscopy and diffraction imaging provides insight into the atomic and sub-atomic structure of matter. They permit determination of the positions of atoms in a crystal lattice or in a molecule as well as the distribution of electrons inside atoms. State-of-the-art time-resolved spectroscopy with femtosecond and attosecond resolution provides access to dynamic changes in the atomic and electronic structure of matter. Our proposal aims at combining these two frontier techniques of XXI century science to make a long-standing dream of scientist come true: the direct observation of atoms and electrons in their natural state: in motion. Shifts in the atoms positions by tens to hundreds of picometers can make chemical bonds break apart or newly form, changing the structure and/or chemical composition of matter. Electronic motion on similar scales may result in the emission of light, or the initiation of processes that lead to a change in physical or chemical properties, or biological function. These motions happen within femtoseconds and attoseconds, respectively. To make them observable, we need a 4-dimensional (4D) imaging technique capable of recording freeze-frame snapshots of microscopic systems with picometer spatial resolution and femtosecond to attosecond exposure time. The motion can then be visualized by slow-motion replay of the freeze-frame shots. The goal of this project is to develop a 4D imaging technique that will ultimately offer picometer resolution is space and attosecond resolution in time.

2 500 000 €

Start date: 2010-03-01, End date: 2015-02-28

Several observed anomalies in neutrino oscillation data can be explained by a hypothetical fourth neutrino separated from the three standard neutrinos by a squared mass difference of a few eV2. This hypothesis can be tested with a PBq (ten kilocurie scale) 144Ce antineutrino beta-source deployed at the center of a large low background liquid scintillator detector, such like Borexino, KamLAND, and SNO+. In particular, the compact size of such a source could yield an energy-dependent oscillating pattern in event spatial distribution that would unambiguously determine neutrino mass differences and mixing angles. The proposed program aims to perform the necessary research and developments to produce and deploy an intense antineutrino source in a large liquid scintillator detector. Our program will address the definition of the production process of the neutrino source as well as its experimental characterization, the detailed physics simulation of both signal and backgrounds, the complete design and the realization of the thick shielding, the preparation of the interfaces with the antineutrino detector, including the safety and security aspects.

1 500 000 €

Start date: 2012-10-01, End date: 2018-09-30

What is the origin of cosmic rays, what are the dominant acceleration mechanisms in relativistic shocks, how do cosmic rays self-consistently influence the shock dynamics, how are relativistic collisionless shocks formed are longstanding scientific questions, closely tied to extreme plasma physics processes, and where a close interplay between the micro-instabilities and the global dynamics is critical. Relativistic shocks are closely connected with the propagation of intense streams of particles pervasive in many astrophysical scenarios. The possibility of exciting shocks in the laboratory will also be available very soon with multi-PW lasers or intense relativistic particle beams. Computational modeling is now established as a prominent research tool, by enabling the fully kinetic modeling of these systems for the first time. With the fast paced developments in high performance computing, the time is ripe for a focused research programme on simulation-based studies of relativistic shocks. This proposal therefore focuses on using self-consistent ab initio massively parallel simulations to study the physics of relativistic shocks, bridging the gap between the multidimensional microphysics of shock onset, formation, and propagation and the global system dynamics. Particular focus will be given to the shock acceleration mechanisms and the radiation signatures of the various physical processes, with the goal of solving some of the central questions in plasma/relativistic phenomena in astrophysics and in the laboratory, and opening new avenues between theoretical/massive computational studies, laboratory experiments and astrophysical observations.

1 588 800 €

Start date: 2011-06-01, End date: 2016-07-31

"An important driver of scientific progress has always been the envisioning of applications far beyond existing technological capabilities. Such thinking creates new challenges for physicists, driven by the groundbreaking nature of the anticipated application. In the case of laser physics, one of these applications is laser wake-field particle acceleration and possible future uses thereof, such as in collider experiments, or for medical applications such as cancer treatment. To accelerate electrons and positrons to TeV-energies, a laser architecture is required that allows for the combination of high efficiency, Petawatt peak powers, and Megawatt average powers. Developing such a laser system would be a challenging task that might take decades of aggressive research, development, and, most important, revolutionary approaches and innovative ideas. The goal of the ACOPS project is to develop a compact, efficient, scalable, and cost-effective high-average and high-peak power ultra-short pulse laser concept. The proposed approach to this goal relies on the spatially and temporally separated amplification of ultrashort laser pulses in waveguide structures, followed by coherent combination into a single train of pulses with increased average power and pulse energy. This combination can be realized through the coherent addition of the output beams of spatially separated amplifiers, combined with the pulse stacking of temporally separated pulses in passive enhancement cavities, employing a fast-switching element as cavity dumper. Therefore, the three main tasks are the development of kW-class high-repetition-rate driving lasers, the investigation of non-steady state pulse enhancement in passive cavities, and the development of a suitable dumping element. If successful, the proposed concept would undoubtedly provide a tool that would allow researchers to surpass the current limits in high-field physics and accelerator science."

1 881 040 €

Start date: 2014-02-01, End date: 2019-01-31

"The proposed research program has three main objectives. The first and second objectives are to seek extreme precisions in optical atomic spectroscopy and optical clocks, and to use this quest as a mean of exploration in atomic physics. The third objective is to explore new possibilities that stem from extreme precision. These goals will be pursued via three complementary activities: #1: Search for extreme precisions with an Hg optical lattice clock. #2: Explore and exploit the rich Hg system, which is essentially unexplored in the cold and ultra-cold regime. #3: Identify new applications of clocks with extreme precision to Earth science. Clocks can measure directly the gravitational potential via Einstein’s gravitational redshift, leading to the idea of “clock-based geodesy”. The 2 first activities are experimental and build on an existing setup, where we demonstrated the feasibility of an Hg optical lattice clock. Hg is chosen for its potential to surpass competing systems. We will investigate the unexplored physics of the Hg clock. This includes interactions between Hg atoms, lattice-induced light shifts, and sensitivity to external fields which are specific to the atomic species. Beyond, we will explore the fundamental limits of the optical lattice scheme. We will exploit other remarkable features of Hg associated to the high atomic number and the diversity of stable isotopes. These features enable tests of fundamental physical laws, ultra-precise measurements of isotope shifts, measurement of collisional properties toward evaporative cooling and quantum gases of Hg, investigation of forbidden transitions promising for measuring the nuclear anapole moment of Hg. The third activity is theoretical and is aimed at initiating collaborations with experts in modelling Earth gravity. With this expertise, we will identify the most promising and realistic approaches for clocks and emerging remote comparison methods to contribute to geodesy, hydrology, oceanography, etc."

1 946 432 €

Start date: 2014-04-01, End date: 2019-03-31

Fundamental interactions in nature are well described by quantum gauge fields in 4 space-time dimensions (4d). When the strength of gauge interaction is weak the Feynman perturbation techniques are very efficient for the description of most of the experimentally observable consequences of the Standard model and for the study of high energy processes in QCD. But in the intermediate and strong coupling regime, such as the relatively small energies in QCD, the perturbation theory fails leaving us with no reliable analytic methods (except the Monte-Carlo simulation). The project aims at working out new analytic and computational methods for strongly coupled gauge theories in 4d. We will employ for that two important discoveries: 1) the gauge-string duality (AdS/CFT correspondence) relating certain strongly coupled gauge Conformal Field Theories to the weakly coupled string theories on Anty-deSitter space; 2) the solvability, or integrability of maximally supersymmetric (N=4) 4d super Yang-Mills (SYM) theory in multicolor limit. Integrability made possible pioneering exact numerical and analytic results in the N=4 multicolor SYM at any coupling, effectively summing up all 4d Feynman diagrams. Recently, we conjectured a system of functional equations - the AdS/CFT Y-system – for the exact spectrum of anomalous dimensions of all local operators in N=4 SYM. The conjecture has passed all available checks. My project is aimed at the understanding of origins of this, still mysterious integrability. Deriving the AdS/CFT Y-system from the first principles on both sides of gauge-string duality should provide a long-awaited proof of the AdS/CFT correspondence itself. I plan to use the Y-system to study the systematic weak and strong coupling expansions and the so called BFKL limit, as well as for calculation of multi-point correlation functions of N=4 SYM. We hope on new insights into the strong coupling dynamics of less supersymmetric gauge theories and of QCD.

1 456 140 €

Start date: 2013-11-01, End date: 2018-10-31

AGEnTh is an interdisciplinary proposal which aims at theoretically investigating atomic many-body systems (cold atoms and trapped ions) in close connection to concepts from quantum information, condensed matter, and high energy physics. The main goals of this programme are to: I) Find to scalable schemes for the measurements of entanglement properties, and in particular entanglement spectra, by proposing a shifting paradigm to access entanglement focused on entanglement Hamiltonians and field theories instead of probing density matrices; II) Show how atomic gauge theories (including dynamical gauge fields) are ideal candidates for the realization of long-sought, highly-entangled states of matter, in particular topological superconductors supporting parafermion edge modes, and novel classes of quantum spin liquids emerging from clustering; III) Develop new implementation strategies for the realization of gauge symmetries of paramount importance, such as discrete and SU(N)xSU(2)xU(1) groups, and establish a theoretical framework for the understanding of atomic physics experiments within the light-from-chaos scenario pioneered in particle physics. These objectives are at the cutting-edge of fundamental science, and represent a coherent effort aimed at underpinning unprecedented regimes of strongly interacting quantum matter by addressing the basic aspects of probing, many-body physics, and implementations. The results are expected to (i) build up and establish qualitatively new synergies between the aforementioned communities, and (ii) stimulate an intense theoretical and experimental activity focused on both entanglement and atomic gauge theories. In order to achieve those, AGEnTh builds: (1) on my background working at the interface between atomic physics and quantum optics from one side, and many-body theory on the other, and (2) on exploratory studies which I carried out to mitigate the conceptual risks associated with its high-risk/high-gain goals.

1 055 317 €

Start date: 2018-05-01, End date: 2023-04-30

In quantum electrodynamics a range of fundamental processes are driven by omnipresent vacuum fluctuations. Photonic crystals can control vacuum fluctuations and thereby the fundamental interaction between light and matter. We will conduct experiments on quantum dots in photonic crystals and observe novel quantum electrodynamics effects including fractional decay and the modified Lamb shift. Furthermore, photonic crystals will be explored for shielding sensitive quantum-superposition states against decoherence. Defects in photonic crystals allow novel functionalities enabling nanocavities and waveguides. We will use the tight confinement of light in a nanocavity to entangle a quantum dot and a photon, and explore the scalability. Controlled ways of generating scalable and robust quantum entanglement is the essential missing link limiting quantum communication and quantum computing. A single quantum dot coupled to a slowly propagating mode in a photonic crystal waveguide will be used to induce large nonlinearities at the few-photon level. Finally we will explore a novel route to enhanced light-matter interaction employing controlled disorder in photonic crystals. In disordered media multiple scattering of light takes place and can lead to the formation of Anderson-localized modes. We will explore cavity quantum electrodynamics in Anderson-localized random cavities considering disorder a resource and not a nuisance, which is the traditional view. The main focus of the project will be on optical experiments, but fabrication of photonic crystals and detailed theory will be carried out as well. Several of the proposed experiments will constitute milestones in quantum optics and may pave the way for all-solid-state quantum communication with quantum dots in photonic crystals.

1 199 648 €

Start date: 2010-12-01, End date: 2015-11-30

The field of disordered quantum gases is developing rapidly. Dramatic progress has been achieved recently and first experimental observation of one-dimensional Anderson localization (AL) of matterwaves has been reported using Bose-Einstein condensates in controlled disorder (in our group at Institut d'Optique and at LENS; Nature, 2008). This dramatic success results from joint theoretical and experimental efforts, we have contributed to. Most importantly, it opens unprecedented routes to pursue several outstanding challenges in the multidisciplinary field of disordered systems, which, after fifty years of Anderson localization, is more active than ever. This theoretical project aims at further developing the emerging field of disordered quantum gases towards novel challenges. Our aim is twofold. First, we will propose and analyze schemes where experiments on ultracold atoms can address unsolved issues: AL in dimensions higher than one, effects of inter-atomic interactions on AL, strongly-correlated disordered gases and quantum simulators for spin systems (spin glasses). Second, by taking into account specific features of ultracold atoms, beyond standard toy-models, we will raise and study new questions which have not been addressed before (eg long-range correlations of speckle potentials, finite-size effects, controlled interactions). Both aspects would open new frontiers to disordered quantum gases and offer new possibilities to shed new light on highly debated issues. Our main concerns are thus to (i) study situations relevant to experiments, (ii) develop new approaches, applicable to ultracold atoms, (iii) identify key observables, and (iv) propose new challenging experiments. In this project, we will benefit from the original situation of our theory team: It is independent but forms part of a larger group (lead by A. Aspect), which is a world-leader in experiments on disordered quantum gases, we have already developed close collaborative relationship with.

985 200 €

Start date: 2011-01-01, End date: 2015-12-31

This project focuses on developing quantum field theory methods and applying them to the phenomenology of elementary particles. At the Large Hadron Collider (LHC) our current best theoretical understanding of particle physics is being tested against experiment by measuring e.g. properties of the recently discovered Higgs boson. With run two of the LHC, currently underway, the experimental accuracy will further increase. Theoretical predictions matching the latter are urgently needed. Obtaining these requires extremely difficult calculations of scattering amplitudes and cross sections in quantum field theory, including calculations to correctly describe large contributions due to long-distance physics in the latter. Major obstacles in such computations are the large number of Feynman diagrams that are difficult to handle, even with the help of modern computers, and the computation of Feynman loop integrals. To address these issues, we will develop innovative methods that are inspired by new structures found in supersymmetric field theories. We will extend the scope of the differential equations method for computing Feynman integrals, and apply it to scattering processes that are needed for phenomenology, but too complicated to analyze using current methods. Our results will help measure fundamental parameters of Nature, such as, for example, couplings of the Higgs boson, with unprecedented precision. Moreover, by accurately predicting backgrounds from known physics, our results will also be invaluable for searches of new particles.

2 000 000 €

Start date: 2017-10-01, End date: 2023-09-30

I propose to use large clouds of cold Ytterbium atoms to observe Anderson localization of light in three dimensions, which has challenged theoreticians and experimentalists for many decades. After the prediction by Anderson of a disorder-induced conductor to insulator transition for electrons, light has been proposed as ideal non interacting waves to explore coherent transport properties in the absence of interactions. The development in experiments and theory over the past several years have shown a route towards the experimental realization of this phase transition. Previous studies on Anderson localization of light using semiconductor powders or dielectric particles have shown that intrinsic material properties, such as absorption or inelastic scattering of light, need to be taken into account in the interpretation of experimental signatures of Anderson localization. Laser-cooled clouds of atoms avoid the problems of samples used so far to study Anderson localization of light. Ab initio theoretical models, available for cold Ytterbium atoms, have shown that the mere high spatial density of the scattering sample is not sufficient to allow for Anderson localization of photons in three dimensions, but that an additional magnetic field or additional disorder on the level shifts can induce a phase transition in three dimensions. The role of disorder in atom-light interactions has important consequences for the next generation of high precision atomic clocks and quantum memories. By connecting the mesoscopic physics approach to quantum optics and cooperative scattering, this project will allow better control of cold atoms as building blocks of future quantum technologies. Time-resolved transport experiments will connect super- and subradiant assisted transmission with the extended and localized eigenstates of the system. Having pioneered studies on weak localization and cooperative scattering enables me to diagnostic strong localization of light by cold atoms.

2 490 717 €

Start date: 2019-10-01, End date: 2024-09-30

The ability of positrons to annihilate with electrons, producing characteristic gamma rays, gives them important use in medicine via positron-emission tomography (PET), diagnostics of industrially-important materials, and in elucidating astrophysical phenomena. Moreover, the fundamental interactions of positrons and positronium (Ps) with atoms, molecules and condensed matter are currently under intensive study in numerous international laboratories, to illuminate collision phenomena and perform precision tests of fundamental laws. Proper interpretation and development of these costly and difficult experiments requires accurate calculations of low-energy positron and Ps interactions with normal matter. These systems, however, involve strong correlations, e.g., polarisation of the atom and virtual-Ps formation (where an atomic electron tunnels to the positron): they significantly effect positron- and Ps-atom/molecule interactions, e.g., enhancing annihilation rates by many orders of magnitude, and making the accurate description of these systems a challenging many-body problem. Current theoretical capability lags severely behind that of experiment. Major theoretical and computational developments are required to bridge the gap. One powerful method, which accounts for the correlations in a natural, transparent and systematic way, is many-body theory (MBT). Building on my expertise in the field, I propose to develop new MBT to deliver unique and unrivalled capability in theory and computation of low-energy positron and Ps interactions with atoms, molecules, and condensed matter. The ambitious programme will provide the basic understanding required to interpret and develop the fundamental experiments, antimatter-based materials science techniques, and wider technologies, e.g., (PET), and more broadly, potentially revolutionary and generally applicable computational methodologies that promise to define a new level of high-precision in atomic-MBT calculations.

1 318 419 €

Start date: 2019-02-01, End date: 2024-01-31

This project enters the experimental investigation of anyonic quantum gases. We will study anyons – conjectured particles with a statistical exchange phase anywhere between 0 and π – in different many-body systems. This progress will be enabled by a unique approach of bringing together artificial gauge fields and quantum gas microscopes for ultracold atoms. Specifically, we will implement the 1D anyon Hubbard model via a lattice shaking protocol that imprints density-dependent Peierls phases. By engineering the statistical exchange phase, we can continuously tune between bosons and fermions and explore a statistically-induced quantum phase transition. We will monitor the continuous fermionization via the build-up of Friedel oscillations. Using state-of-the-art cold atom technology, we will thus open the physics of anyons to experimental research and address open questions related to their fractional exclusion statistics. Secondly, we will create fractional quantum Hall systems in rapidly rotating microtraps. Using the quantum gas microscope, we will i) control the optical potentials at a level which allows approaching the centrifugal limit and ii) use small atom numbers equal to the inserted angular momentum quantum number. The strongly-correlated ground states such as the Laughlin state can be identified via their characteristic density correlations. Of particular interest are the quasihole excitations, whose predicted anyonic exchange statistics have not been directly observed to date. We will probe and test their statistics via the characteristic counting sequence in the excitation spectrum. Furthermore, we will test ideas to transfer anyonic properties of the excitations to a second tracer species. This approach will enable us to both probe the fractional exclusion statistics of the excitations and to create a 2D anyonic quantum gas. In the long run, these techniques open a path to also study non-Abelian anyons with ultracold atoms.

1 497 500 €

Start date: 2019-01-01, End date: 2023-12-31

The goal of this project is to prepare in a deterministic way, and then to characterize, various entangled states of up to 25 individual atoms held in an array of optical tweezers. Such a system provides a new arena to explore quantum entangled states of a large number of particles. Entanglement is the existence of quantum correlations between different parts of a system, and it is recognized as an essential property that distinguishes the quantum and the classical worlds. It is also a resource in various areas of physics, such as quantum information processing, quantum metrology, correlated quantum systems and quantum simulation. In the proposed design, each site is individually addressable, which enables single atom manipulation and detection. This will provide the largest entangled state ever produced and fully characterized at the individual particle level. The experiment will be implemented by combining two crucial novel features, that I was able to demonstrate very recently: first, the manipulation of quantum bits written on long-lived hyperfine ground states of single ultra-cold atoms trapped in microscopic optical tweezers; second, the generation of entanglement by using the strong long-range interactions between Rydberg states. These interactions lead to the so-called dipole blockade , and enable the preparation of various classes of entangled states, such as states carrying only one excitation (W states), and states analogous to Schrödinger s cats (GHZ states). Finally, I will also explore strategies to protect these states against decoherence, developed in the framework of fault-tolerant and topological quantum computing. This project therefore combines an experimental challenge and the exploration of entanglement in a mesoscopic system.

1 449 600 €

Start date: 2009-12-01, End date: 2014-11-30

Physical systems featuring strong electronic correlations exhibit fascinating phenomena, as exemplified by high-Tc superconductivity, quantum magnetism or fractional quantum Hall physics. Inspired by these effects, new ideas have emerged to harness strongly correlated phases in artificial quantum materials, and use them as a resource for fundamental science and for quantum technology. Promising approaches for producing quantum devices are found in condensed matter platforms: one can indeed benefit from nanofabrication to engineer systems that are compact, versatile, and which can potentially be integrated in large-scale architectures. The main goal of ARQADIA is to engineer and study quantum correlated and topological phases of light using artificial photonic materials that I will fabricate in a solid-state platform. I will use exciton-polaritons in semiconductor microcavities, which are hybrid quasiparticles resulting from strong coupling between cavity photons and quantum well excitons. Polaritons are particularly attractive since they combine the best of two worlds: (i) through their photon component, they can be confined in microstrucutres and manipulated using optical spectroscopy; (ii) through their matter component, interactions between polaritons can be tuned and reinforced. Moreover, polaritons can be detected through the decay of cavity photons, which means that they naturally implement out-of-equilibrium physics and allow addressing fascinating questions related to the interplay between quantum correlations and dissipation. Within ARQADIA, I will tackle the challenge of engineering quantum correlations between polaritons via a technological breakthrough: I will insert active materials featuring strongly interacting excitons in microcavity lattices. I will use these materials to study out-of-equilibrium strongly correlated phases in vastly different regimes: from 1D to 2D, from weakly to strongly interacting and from topologically trivial to non-trivial.

1 499 603 €

Start date: 2021-01-01, End date: 2025-12-31

The main goal of ASTRUm is to employ stored and cooled radioactive ions for forefront nuclear astrophysics research. Four key experiments are proposed to be conducted at GSI in Darmstadt, which holds the only facility to date capable of storing highly charged radionuclides in the required element and energy range. The proposed experiments can hardly be conducted by any other technique or method. The weak decay matrix element for the transition between the 2.3 keV state in 205Pb and the ground state of 205Tl will be measured via the bound state beta decay measurement of fully ionized 205Tl81+. This will provide the required data to determine the solar pp-neutrino flux integrated over the last 5 million years and will allow us to unveil the astrophysical conditions prior to the formation of the solar system. The measurements of the alpha-decay width of the 4.033 MeV excited state in 19Ne will allow us to constrain the conditions for the ignition of the rp-process in X-ray bursters. ASTRUm will open a new field by enabling for the first time measurements of proton- and alpha-capture reaction cross-sections on radioactive nuclei of interest for the p-process of nucleosynthesis. Last but not least, broad band mass and half-life measurements in a ring is the only technique to precisely determine these key nuclear properties for nuclei with half-lives as short as a millisecond and production rates of below one ion per day. To accomplish these measurements with highest efficiency, sensitivity and precision, improved detector systems will be developed within ASTRUm. Possible applications of these systems go beyond ASTRUm objectives and will be used in particular in accelerator physics. The instrumentation and experience gained within ASTRUm will be indispensable for planning the future, next generation storage ring projects, which are launched or proposed at several radioactive ion beam facilities.

1 874 750 €

Start date: 2016-04-01, End date: 2021-09-30

Gauge theories play a central role in particle and condensed matter physics. Heavy-ion collisions explore the strong dynamics of quarks and gluons, which also governs the deep interior of neutron stars, while strongly correlated electrons determine the physics of high-temperature superconductors and spin liquids. Numerical simulations of such systems are often hindered by sign problems. In quantum link models - an alternative formulation of gauge theories developed by the applicant - gauge fields emerge from discrete quantum variables. In the past year, in close collaboration with atomic physicists, we have established quantum link models as a framework for the atomic quantum simulation of dynamical gauge fields. Abelian gauge theories can be realized with Bose-Fermi mixtures of ultracold atoms in an optical lattice, while non-Abelian gauge fields arise from fermionic constituents embodied by alkaline-earth atoms. Quantum simulators, which do not suffer from the sign problem, shall be constructed to address non-trivial dynamics, including quantum phase transitions in spin liquids, the real-time dynamics of confining strings as well as of chiral symmetry restoration at finite temperature and baryon density, baryon superfluidity, or color-flavor locking. New classical simulation algorithms shall be developed in order to solve severe sign problems, to investigate confining gauge theories, and to validate the proposed quantum simulators. Starting from U(1) and SU(2) gauge theories, an atomic physics tool box shall be developed for quantum simulation of gauge theories of increasing complexity, ultimately aiming at 4-d Quantum Chromodynamics (QCD). This project is based on innovative ideas from particle, condensed matter, and computational physics, and requires an interdisciplinary team of researchers. It has the potential to drastically increase the power of simulations and to address very challenging problems that cannot be solved with classical simulation methods.

1 975 242 €

Start date: 2014-02-01, End date: 2019-01-31

The astrophysical p-process, the stellar production mechanism of the heavy, proton rich isotopes (p-isotopes), is one of the least studied processes in nucleosynthesis. The astrophysical site(s) for the p-process could not yet be clearly identified. In order to reproduce the natural abundances of the p-isotopes, the p-process models must take into account a huge nuclear reaction network. A precise knowledge of the rate of the nuclear reactions in this network is essential for a reliable abundance calculation and for a clear assignment of the astrophysical site(s). For lack of experimental data the nuclear physics inputs for the reaction networks are based on statistical model calculations. These calculations are largely untested in the mass and energy range relevant to the p-process and the uncertainties in the reaction rate values result in a correspondingly uncertain prediction of the p-isotope abundances. Therefore, experiments aiming at the determination of reaction rates for the p-process are of great importance. In this project nuclear reaction cross section measurements will be carried out in the mass and energy range of p-process to check the reliability of the statistical model calculations and to put the p-process models on a more reliable base. The accelerators of the Institute of Nuclear Research in Debrecen, Hungary provide the necessary basis for such studies. The p-process model calculations are especially sensitive to the rates of reactions involving alpha particles and heavy nuclei. Because of technical difficulties, so far there are practically no experimental data available on such reactions and the uncertainty in these reaction rates is presently one of the biggest contributions to the uncertainty of p-isotope abundance calculations. With the help of the ERC grant the alpha-induced reaction cross sections can be measured on heavy isotopes for the first time, which could contribute to a better understanding of the astrophysical p-process.

750 000 €

Start date: 2008-07-01, End date: 2013-06-30

Coherence is a fundamental property of quantum mechanics, characterizing phase correlations of light or matter waves. It is at the heart of many physical phenomena, such as the creation of electron-hole pairs in the photovoltaic effect or the fast migration of electronic charge within a molecule. In order to study coherent electron dynamics, extremely high spatial and temporal resolving power is required, which is highly challenging. Well-established imaging methods like scanning tunneling microscopy achieve atomic-scale spatial resolution, while lacking ultrafast time resolution. At the temporal frontier, I recently bridged the gap between attosecond spectroscopy (1as = 10-18 s) and the nano-scale. The goal of my research program is to unlock the full potential of attosecond spectroscopy by achieving simultaneous spatial and temporal probing of ultrafast coherent phenomena. The proposed approach relies on the introduction of attosecond spectroscopy into scanning tunneling microscopy and electron holography. The spatial resolution of these methods is based on nano-scale needle tips, serving as local probes or as point-like electron sources. My team and I will develop attosecond temporal gates at the tips, enabling pump-probe spectroscopy. The resulting “pump” – triggering the coherent dynamics – and the “probe” – measuring its evolution – are localized in space and time, with attosecond and sub-nanometer precision. This combination will allow watching charge dynamics in a single molecule and observing multi-electron dynamics in nanostructures with atomic-scale site selectivity, as they evolve in real time. My approach has the potential to shed new light on quantum optics, plasmonics, molecular electronics, surface science and femtochemistry. In particular, my team and I will study quantum tunneling on the atomic level, charge migration in organic molecules and electron-hole dynamics in low-dimensional solid-state systems.

1 690 323 €

Start date: 2020-01-01, End date: 2024-12-31

By enabling the conversion of forces into measurable displacements, mechanical oscillators have always played a central role in experimental physics. Recent developments in the PI group demonstrated the possibility to realize ultrasensitive and vectorial force field sensing by using suspended SiC nanowires and optical readout of their transverse vibrations. Astonishing sensitivities were obtained at room and dilution temperatures, at the Atto- Zepto-newton level, for which the electron-electron interaction becomes detectable at 100µm. The goal of the project is to push forward those ultrasensitive nano-optomechanical force sensors, to realize even more challenging explorations of novel fundamental interactions at the quantum-classical interface. We will develop universal advanced sensing protocols to explore the vectorial structure of fundamental optical, electrostatic or magnetic interactions, and investigate Casimir force fields above nanostructured surfaces, in geometries where it was recently predicted to become repulsive. The second research axis is the one of cavity nano-optomechanics: inserting the ultrasensitive nanowire in a high finesse optical microcavity should enhance the light-nanowire interaction up to the point where a single cavity photon can displace the nanowire by more than its zero point quantum fluctuations. We will investigate this so-called ultrastrong optomechanical coupling regime, and further explore novel regimes in cavity optomechanics, where optical non-linearities at the single photon level become accessible. The last part is dedicated to the exploration of hybrid qubit-mechanical systems, in which nanowire vibrations are magnetically coupled to the spin of a single Nitrogen Vacancy defect in diamond. We will focus on the exploration of spin-dependent forces, aiming at mechanically detecting qubit excitations, opening a novel road towards the generation of non-classical states of motion, and mechanically enhanced quantum sensors.

2 067 905 €

Start date: 2019-09-01, End date: 2024-08-31

Collective electron motion can unfold on attosecond time scales in nanoplasmonic systems, as defined by the inverse spectral bandwidth of the plasmonic resonant region. Similarly, in dielectrics or semiconductors, the laser-driven collective motion of electrons can occur on this characteristic time scale. Until now, such collective electron dynamics has not been directly observed on its natural, attosecond timescale. In ATTOCO, the attosecond, sub-cycle dynamics of strong-field driven collective electron dynamics in clusters and nanoparticles will be explored. Moreover, we will explore field-dependent processes induced by strong laser fields in nanometer sized matter, such as the metallization of dielectrics, which has been recently proposed theoretically. In order to map the collective electron motion we will apply the attosecond nanoplasmonic streaking technique, which has been proposed and developed theoretically. In this approach, the temporal resolution is achieved by limiting the emission of high energetic, direct photoelectrons to a sub-cycle time window using attosecond XUV pulses phase-locked to a driving few-cycle near-infrared field. Kinetic energy spectra of the photoelectrons recorded for different delays between the excitation field and the ionizing XUV pulse will allow extracting the spatio-temporal electron dynamics. ATTOCO offers the capability to measure field-induced material changes in real-time and to gain novel insight into collective electron dynamics. In particular, we aim to learn from ATTOCO in detail, how the collective electron motion is established, how the collective motion is driven by the strong external field and over which pathways and timescale the collective motion decays. ATTOCO provides also a major step in the development of lightwave (nano-)electronics, which may push the frontiers of electronics from multi-gigahertz to petahertz frequencies. If successfully accomplished, this development will herald the potential scalability of electron-based information technologies to lightwave frequencies, surpassing the speed of current computation and communication technology by many orders of magnitude.

1 498 500 €

Start date: 2013-06-01, End date: 2018-05-31

Light is one of today’s most powerful tools for exploriLight is one of today’s most powerful tools for exploring nature at the frontier of the human knowledge. The rapid development of laser technology allow us today to generate ultrashort pulses of coherent structured light: light fields with custom spatial and temporal properties, such as intensity, phase and angular momentum. The later one represents one of the most interesting light properties nowadays, as topological light beams carrying angular momentum interact with matter differently, introducing mechanical motion to micro and nano-structures, and affecting fundamental excitation rules. High-order harmonic generation (HHG) stands as a unique mechanism to provide coherent flashes of light with outstanding properties: its radiation spectrum expands from the vacuum ultraviolet to the soft x-rays; it can be synthesized in pulses as short as several attoseconds (10^-18 seconds): and it can be structured in its angular momentum properties. This proposal represents a timely opportunity to explore the ground-breaking opportunities offered by attosecond structured x-ray sources. It conveys computing light-matter interaction in extreme conditions, which requires an extraordinary effort in the elaboration of new theoretical tools to design, propose and guide future experiments at the frontier of ultrafast science. We shall pioneer the new scenario of angular momenta in structured ultrashort x-rays –the most complex coherent pulses to date–. It is not difficult to envision a new era in ultrafast nanotechnology that makes use of these x-ray sources. In particular we shall pioneer their application to nanoscience and ultrafast magnetism. We aim to establish the grounding principles of attomagnetism, taking advantage of the unique opportunity offered by structured light pulses to induce pure attosecond magnetic fields, which could set the precedents of high-rate magnetic recording through ultrafast magnetization reversal.

1 425 000 €

Start date: 2020-03-01, End date: 2025-02-28

Axions are hypothetical particles whose existence would solve two major problems: the strong P, T problem (a major blemish on the standard model); and the dark matter problem. It is a most important goal to either observe or rule out the existence of a cosmic axion background. It appears that decisive observations may be possible, but only after orchestrating insight from specialities ranging from quantum field theory and astrophysical modeling to ultra-low noise quantum measurement theory. Detailed predictions for the magnitude and structure of the cosmic axion background depend on cosmological and astrophysical modeling, which can be constrained by theoretical insight and numerical simulation. In parallel, we must optimize strategies for extracting accessible signals from that very weakly interacting source. While the existence of axions as fundamental particles remains hypothetical, the equations governing how axions interact with electromagnetic fields also govern (with different parameters) how certain materials interact with electromagnetic fields. Thus those materials embody “emergent” axions. The equations have remarkable properties, which one can test in these materials, and possibly put to practical use. Closely related to axions, mathematically, are anyons. Anyons are particle-like excitations that elude the familiar classification into bosons and fermions. Theoretical and numerical studies indicate that they are common emergent features of highly entangled states of matter in two dimensions. Recent work suggests the existence of states of matter, both natural and engineered, in which anyon dynamics is both important and experimentally accessible. Since the equations for anyons and axions are remarkably similar, and both have common, deep roots in symmetry and topology, it will be fruitful to consider them together.

2 324 391 €

Start date: 2017-09-01, End date: 2022-08-31

Pseudoscalar QCD axions and axion-like Particles (ALPs) are an excellent candidate for Dark Matter or can act as a mediator particle for Dark Matter. Since the discovery of the Higgs boson, we know that fundamental scalars exist and it is timely to explore the Axion/ALP parameter space more intensively. A look at the allowed axion/ALP parameter space makes it clear that these might exist at low mass (below few eV), as (part of) Dark Matter. Alternatively they might exist at higher mass, above roughly the MeV scale, potentially as a Dark Matter mediator particle. AxScale explores parts of these different mass regions, with complementary techniques but with one research team. Firstly, with RADES, it develops a novel concept for a filter-like cavity for the search of QCD axion Dark matter at a few tens of a micro-eV. Dark Matter Axions can be discovered by their resonant conversion in that cavity embedded in a strong magnetic field. The `classical axion window' has recently received much interest from cosmological model-building and I will implement a novel cavity concept that will allow to explore this Dark Matter parameter region. Secondly, AxScale searches for axions and ALPs using the NA62 detector at CERN's SPS. Especially the mass region above a few MeV can be efficiently searched by the use of a proton fixed-target facility. During nominal data taking NA62 investigates a Kaon beam. NA62 can also run in a mode in which its primary proton beam is fully dumped. With the resulting high interaction rate, the existence of weakly coupled particles can be efficiently probed. Thus, searches for ALPs from Kaon decays as well as from production in dumped protons with NA62 are foreseen in AxScale. More generally, NA62 can look for a plethora of `Dark Sector' particles with recorded and future data. With the AxScale program I aim at maximizing the reach of NA62 for these new physics models.

1 134 375 €

Start date: 2018-11-01, End date: 2023-10-31

My research encompasses the application of novel methods and strategies in the field of low energy particle physics. The goal of the presented program is to lead an independent and highly competitive experiment to search for a CP violating neutron electric dipole moment (nEDM), as well as for new exotic interactions using highly sensitive neutron and proton spin resonance techniques. The measurement of the nEDM is considered to be one of the most important fundamental physics experiments at low energy. It represents a promising route for finding new physics beyond the standard model (SM) and describes an important search for new sources of CP violation in order to understand the observed large baryon asymmetry in our universe. The main project will follow a novel concept based on my original idea, which plans to employ a pulsed neutron beam at high intensity instead of the established use of storable ultracold neutrons. This complementary and potentially ground-breaking method provides the possibility to distinguish between the signal due to a nEDM and previously limiting systematic effects, and should lead to an improved result compared to the present best nEDM beam experiment. The findings of these investigations will be of paramount importance and will form the cornerstone for the success of the full-scale experiment intended for the European Spallation Source. A second scientific question will be addressed by performing spin precession experiments searching for exotic short-range interactions and associated light bosons. This is a vivid field of research motivated by various extensions to the SM. The goal of these measurements, using neutrons and protons, is to search for additional interactions such new bosons mediate between ordinary particles. Both topics describe ambitious and unique efforts. They use related techniques, address important questions in fundamental physics, and have the potential of substantial scientific implications and high-impact results.

1 404 062 €

Start date: 2017-04-01, End date: 2022-03-31

Despite large advances in both algorithms and computer technology, even typical instances of computationally hard problems are too difficult to be solved on today’s computers. Unconventional computational devices that break with the usual paradigms of digital electronic computers can help to overcome these limitations. In this project, a network of coupled photon Bose-Einstein condensates will be developed and used as experimental platform to perform ultrafast simulations of classical spin systems. Specifically, the network will be capable of solving the ground-state problem in spin glasses (disordered magnets). The latter constitutes a well-known combinatorial problem that can be mapped mathematically to many other computationally hard problems in machine learning, logistics, computer chip design and DNA sequencing. In a proof-of-principle experiment, I aim to demonstrate that the proposed spin glass simulator performs this computationally hard optimisation problem significantly faster than any other computer today. I have pioneered the Bose-Einstein condensation of photons in optical microcavities, which has enabled us to investigate this genuine quantum-mechanical effect with all-optical methods. In a recent work of my group, we experimentally demonstrate controllable phase relations between photon Bose-Einstein condensates in an optical microcavity. The investigated device realises an optical analogue of a Josephson junction. Similar to a transistor for electronics, a controllable photonic Josephson junction represents the key component for ultrafast optical spin glass simulation and, thus, is the crucial basis for the proposed project. The BEC-NETWORKS project will be the main research project of my research group at the University of Twente.

2 000 000 €

Start date: 2021-02-01, End date: 2026-01-31

BINGO will set the grounds for a large-scale bolometric experiment searching for neutrinoless double beta decay with a background index of about 10-5 counts/(keV kg y) and with very high energy resolution – of the order of 1.5‰ – in the region of interest. These features will enable a search for lepton number violation with unprecedented sensitivity. The BINGO approach can lead to the demonstration of the Majorana nature of neutrino even in the unfavourable case of direct ordering of neutrino masses. BINGO is based on luminescent bolometers for the rejection of the dominant alpha surface background. It will focus on two extremely promising isotopes – 100Mo and 130Te – that have complementary merits and deserve to be both considered for future large-scale searches. The project will bring three original ingredients to the well-established technology of hybrid heat-light bolometers: i) the light-detector sensitivity will be increased by an order of magnitude thanks to Neganov-Luke amplification; (ii) a revolutionary detector assembly will reduce the total surface radioactivity contribution by at least one order of magnitude; (iii) for the first time in an array of macrobolometers, an internal active shield, based on ultrapure ZnWO4 scintillators with bolometric light readout, will suppress the external gamma background. These challenging technologies will be extensively tested in a two-isotope demonstrator, dubbed MINI‑BINGO, which will be located in an underground laboratory in a dedicated cryogenic infrastructure built with ERC funds. The BINGO approach can be implemented in the next-generation search CUPID, a proposed follow up of the CUORE experiment. BINGO can improve dramatically the sensitivity of CUPID, using two isotopes at the same time and providing the demonstration of its background goal. Subsequently, the intrinsic modularity of the bolometric technique would make sensible to proceed to further expansions, capable of penetrating the direct-ordering band.

2 420 370 €

Start date: 2020-10-01, End date: 2025-09-30

Breakthroughs in numerical relativity in 2005 gave us unprecedented access to the strong-field regime of general relativity, making possible solutions of the full nonlinear Einstein equations for the merger of two black holes. Numerical relativity is also crucial to study fundamental physics with gravitational-wave (GW) observations: numerical solutions allow us to construct models that will be essential to extract physical information from observations in data from Advanced LIGO and Virgo, which will operate from late 2015. Complete signal models will allow us to follow up our first theoretical predictions of the nature of black-hole mergers with their first observational measurements. The goal of this project is to advance numerical-relativity methods, deepen our understanding of black-hole mergers, and map the parameter space of binary configurations with the most comprehensive and systematic set of numerical calculations performed to date, in order to produce a complete GW signal model. Central to this problem is the purely general-relativistic effect of orbital precession. The inclusion of precession in waveform models is the most challenging and urgent theoretical problem in the build-up to GW astronomy. Simulations must cover a seven-dimensional parameter space of binary configurations, but their computational cost makes a naive covering unfeasible. This project capitalizes on a breakthrough preliminary model produced by my team in 2013, with the pragmatic goal of focussing on the physics that will be measurable with GW detectors over the next five years. My team at Cardiff is uniquely placed to tackle this problem. Since 2005 I have been at the forefront of black-hole simulations and waveform modelling, and the Cardiff group is a world leader in analysis of GW detector data. This project will consolidate my team to make breakthroughs in strong-field gravity, astrophysics, fundamental physics and cosmology using GW observations.

1 998 009 €

Start date: 2015-10-01, End date: 2022-03-31

Exchange of information between different brains usually takes place through the interaction between bodies and the external environment. The ultimate goal of this project is to establish a novel paradigm of brain-to-brain communication based on direct full-optical recording and controlled stimulation of neuronal activity in different subjects. To pursue this challenging objective, we propose to develop optical technologies well beyond the state of the art for simultaneous neuronal “reading” and “writing” across large volumes and with high spatial and temporal resolution, targeted to the transfer of advantageous behaviour in physiological and pathological conditions. We will perform whole-brain high-resolution imaging in zebrafish larvae to disentangle the activity patterns related to different tasks. We will then use these patterns as stimulation templates in other larvae to investigate spatio-temporal subject-invariant signatures of specific behavioural states. This ‘pump and probe’ strategy will allow gaining deep insights into the complex relationship between neuronal activity and subject behaviour. To move towards clinics-oriented studies on brain stimulation therapies, we will complement whole-brain experiments in zebrafish with large area functional imaging and optostimulation in mammals. We will investigate all-optical brain-to-brain information transfer to boost an advantageous behaviour, i.e. motor recovery, in a mouse model of stroke. Mice showing more effective responses to rehabilitation will provide neuronal activity templates to be elicited in other animals, in order to increase rehabilitation efficiency. We strongly believe that the implementation of new technologies for all-optical transfer of behaviour between different subjects will offer unprecedented views of neuronal activity in healthy and injured brain, paving the way to more effective brain stimulation therapies.

2 370 250 €

Start date: 2016-12-01, End date: 2022-05-31

Elementary particle physics is entering a spectacular new era in which experiments at the Large Hadron Collider (LHC) at CERN will soon start probing some of the deepest questions in physics, such as: Why is gravity so weak? Do elementary particles have substructure? What is the origin of mass? Are there new dimensions? Can we produce black holes in the lab? Could there be other universes with different physical laws? While the LHC pushes the energy frontier, the unprecedented precision of Atom Interferometry, has pointed me to a new tool for fundamental physics. These experiments based on the quantum interference of atoms can test General Relativity on the surface of the Earth, detect gravity waves, and test short-distance gravity, charge quantization, and quantum mechanics with unprecedented precision in the next decade. This ERC Advanced grant proposal is aimed at setting up a world-leading European center for development of a deeper theory of fundamental physics. The next 10 years is the optimal time for such studies to benefit from the wealth of new data that will emerge from the LHC, astrophysical observations and atom interferometry. This is a once-in-a-generation opportunity for making ground-breaking progress, and will open up many new research horizons.

2 200 000 €

Start date: 2009-05-01, End date: 2014-04-30

I received I received the prestigious Inaba award by the lidar community for advancing lidar entomology. Our Scheimpflug lidar can be implemented at 1% of the conventional cost and weight. It allows atmospheric observation with unpreceded sensitivity and spatiotemporal resolution. The kHz sampling rates can exceed the round-trip time of the light and reveal the modulation spectra for classifying free flying insect species over ground. The method has infinite focal depth and efficiently profiles sparse organisms in the airspace with 100000 observations per day. This tool is of key importance for tackling challenges related to pollinator diversity, agricultural pests and pesticides and malaria disease vectors. As in radar entomology, in situ lidar monitoring apparently has inevitable limitations: 1) Detection limit deteriorate with range, and far observations are biased towards larger organisms, 2) It takes several wing-beats, and therefore time, beam-width and energy to retrieve a modulation spectrum for classifying species. I propose to remove range biasing and classify insects by a microsecond flash of light. Back-lasing in air has been a dream of physicists for half a century. I now intend to capture specular reflexes from flat wing membranes. When the surface normal coincides with the lidar transect, collimated back-propagating laser light is accomplished. This flash of light is spectrally fringed and can report on the membrane thickness for target classification purpose. This project has three ambitious milestones of increasing challenge with in situ campaigns: A) Polarimetric kHz lidar: Verification of specular flashes, investigation of range dependence, properties and likelihood. B) Remote nanoscopy: Spectral analysis of remotely retrieved flashes for membrane thickness assessment and optimization of back-scatter resonance. C) Farfetched flatness: I will enhance apparent surface roughness and collimated back-scatter from diffuse specimen by infrared methods

1 499 487 €

Start date: 2020-02-01, End date: 2025-01-31

The interplay between two of the most important building blocks of nature, quantum mechanics and gravity, has been a great source of inspiration for theoretical physics, leading to discoveries such as the Hawking radiation of black holes and the development of string theory. In turn, the following picture emerged: physics at the most fundamental level is governed by the rules of quantum mechanics while gravity is some effective coarse-grained description of the underlying microscopic theory. Given that the microscopic degrees of freedom are non-local, standard techniques such as the renormalization group and effective field theory a priori do not apply. Nevertheless, we use effective field theories that incorporate general relativity to describe our observations. With the discovery of gravitational waves and the various ongoing and upcoming experiments that will put general relativity to the test, it has become urgent to assess the validity of the standard framework of effective field theory for describing observable quantum gravity effects. Recent developments in resolving the information loss paradox and the quantum nature of black holes concluded that effective field theory must be modified in a way that uniquely incorporates quantum gravity. The main purpose of this proposal is to describe this modification in a precise and quantitative way, ultimately connecting it to potential experimental discoveries. In order to achieve this goal, I will approach the problem using a combination of thermodynamics, hydrodynamics and quantum information theory, mostly in the context of the AdS/CFT correspondence, where a precise description of quantum gravity is available. As a by-product of identifying observational features of quantum gravity, I will also make substantial progress in several foundational problems. My broad track record and expertise, and the fact that I have already obtained promising preliminary results, makes me uniquely qualified to lead this endeavor.

2 500 000 €

Start date: 2019-09-01, End date: 2024-08-31

Ever since the Higgs boson was discovered at the LHC in 2012, we had the confirmation that the Standard Model (SM) of particle physics has to be extended. In parallel, the long lasting Dark Matter (DM) problem, supported by a wealth of evidence ranging from precision cosmology to local astrophysical observations, has been suggesting that new particles should exist. Unfortunately, neither the LHC nor the DM dedicated experiments have significantly detected any exotic signals pointing toward a particular new physics extension of the SM so far. With this proposal, I want to take a new path in the quest of new physics searches by providing the first high-precision measurement of the neutral current Coherent Elastic Neutrino-Nucleus Scattering (CENNS). By focusing on the sub-100 eV CENNS induced nuclear recoils, my goal is to reach unprecedented sensitivities to various exotic physics scenarios with major implications from cosmology to particle physics, beyond the reach of existing particle physics experiments. These include for instance the existence of sterile neutrinos and of new mediators, that could be related to the DM problem, and the possibility of Non Standard Interactions that would have tremendous implications on the global neutrino physics program. To this end, I propose to build a kg-scale cryogenic tabletop neutrino experiment with outstanding sensitivity to low-energy nuclear recoils, called CryoCube, that will be deployed at an optimal nuclear reactor site. The key feature of this proposed detector technology is to combine two target materials: Ge-semiconductor and Zn-superconducting metal. I want to push these two detector techniques beyond the state-of-the-art performance to reach sub-100 eV energy thresholds with unparalleled background rejection capabilities. As my proposed CryoCube detector will reach a 5-sigma level CENNS detection significance in a single day, it will be uniquely positioned to probe new physics extensions beyond the SM.

1 495 000 €

Start date: 2019-02-01, End date: 2024-01-31

Conformal Field Theory (CFT) was originally conceived in four and three dimensions, with applications to particle physics and critical phenomena in mind. However, it is in two dimensions that the most spectacular results have been obtained. In higher dimensions, there used to be a general feeling that the constraining power of conformal symmetry by itself is insufficient to tell nontrivial things about the dynamics. Hence the interest in various additional assumptions. This is not fully satisfactory, since there are likely many CFTs that do not fulfill any of them. The main focus of this proposal is to take a fresh look at the idea that the mathematical structure of CFTs is instead such a strong constraint that it can allow for a complete solution of the theory. This program, known as conformal bootstrap, has provided a new element in the quantum field theory toolbox to describe genuine non-perturbative cases. This project aims to explore new directions and push forward the frontiers of conformal filed theories, with the ultimate objective of a detailed classification and understanding of scale invariant systems and their properties. CFT-MAP will develop more efficient numerical techniques and complementary analytical tools making use of two main methods: by studying correlation functions of operators present in any quantum field theory, such as global symmetry conserved currents and the energy momentum tensor; by inspecting the analytical structure of correlation functions. The project will scan the landscape of CFTs, identifying where and how they exist. By significantly improving over the methods at disposal, this proposal will be able to study theories currently are out of reach. Besides the innovative methodologies, a fundamental outcome of CFT-MAP will be a word record determination of critical exponents in second phase transition, together with additional information that allows an approximate reconstruction of the QFT in the neighborhood of fixed points.

1 500 000 €

Start date: 2018-03-01, End date: 2023-02-28

General relativity, Einstein's celebrated theory, has been very successful as a theory of the gravitational interaction. However, within the course of the last decades several issues have been pointed out as indicating its limitations: the inevitable existence of spacetime singularities and the fact that it is not a renormalizable theory manifest as shortcomings at very small scales. The inability of the theory to explain the late time accelerated expansion of the universe or the rotational curves of galaxies without the need of unobserved, mysterious forms of matter/energy can be interpreted as shortcomings at large scales. These riddles make gravity by far the most enigmatic of interactions nowadays. Therefore, the understanding of gravity beyond general relativity seems to be more pertinent than ever. We propose to address this difficult issue by considering a synthetic approach towards the understand of the limitations of general relativity and the study of phenomenology which is usually considered to be outsides its realm. The proposed directions include, but are not limited to: the study of quantum gravity candidates and their phenomenology; extensions or modifications of general relativity which may address renormalizability issues or cosmological observations; explorations of fundamental principles of general relativity and the possible violation of such principles; the study of the implications of deviations from Einstein's theory for astrophysics and cosmology and the possible ways to constrain such deviations; and the study of effects within the framework of general relativity which lie at the limit of its validity as a gravity theory. The deeper understanding of each of these issues will provide an important piece to the puzzle. The synthesis of this pieces is most likely to significantly aid our understanding of gravity, and this is our ultimate goal.

1 375 226 €

Start date: 2012-08-01, End date: 2018-01-31

Why the Universe is void of anti-matter is one of the remaining Big Questions in Science.One explanation is provided within the Standard Model by violation of Charge Parity (CP) symmetry, producing differences between the behavior of particles and their anti-particles.CP violation in the neutrino sector could allow a mechanism by which the matter-anti matter asymmetry arose.The objective of this proposal is to enable a step change in our sensitivity to CP violation in the neutrino sector. I have pioneered the concepts and led the deployment of a small prototype using a novel approach which could eventually lead to the construction of a revolutionary Mega-ton scale Water Cherenkov (WC) neutrino detector.The goal of my research program is to demonstrate the feasibility of this approach via the construction of an intermediate sized prototype with an expandable fiducial mass of up to 10-20kt. It will use a low-cost and lightweight structure, filled with purified water and submerged for mechanical strength and cosmic ray shielding in a 60m deep flooded mine pit in the path of Fermilab’s NuMI neutrino beam in N. Minnesota.The European contribution to this experiment will be profound and definitive.Applying the idea of fast timing and good position resolution of small photodetectors, already pioneered in Europe, in place of large-area photodetector, we will revolutionize WC design.The game-changing nature of this philosophy will be demonstrated via the proof of the detector construction and the observation of electron neutrino events form the NuMI beam.The successful completion of this R&D program will demonstrate a factor of up to 100 decrease in cost compared to conventional detectors and the proof that precision neutrino measurements could be made inside a few years rather than the presently needed decades. The project describes a five year program of work amounting to a total funding request of €3.5M, including an extra €1M of equipment funds.

3 500 000 €

Start date: 2016-10-01, End date: 2022-09-30

Cold gases of electronically excited Rydberg atoms and groundstate polar molecules have generated considerable interest in cold matter physics, by introducing for the first time many-body systems with interactions which are both long-range and tunable with external fields. The overall objective of this proposal is (i) the development of theoretical ideas and tools for the understanding and control of non-equilibrium dynamics in these diverse systems and in their mixtures, including dissipative effects leading to cooling, and (ii) to analyse emerging fundamental phenomena in the classical and quantum regimes of strong interactions, leading to innovative simulations and experiments of complex classical and quantum systems. The project is divided into three parts, with strong overlap: 1) Rydberg atom dynamics: The study of complex open-system dynamics in gases of laser-driven Rydberg atoms, including the study of the effects and control of dissipation and decoherence from spontaneous emission in strongly interacting gases. 2) Cooling of complex molecules in atom-molecule mixtures: The theoretical investigation of novel ways to perform cooling towards quantum degeneracy of generic, comparatively complex molecules, beyond bialkali ones, in mixtures of groundstate molecules and of Rydberg-excited atoms. 3) Simulations of strongly interacting many-body systems at the quantum/classical crossover: Atomistic characterization of formation and dynamics of formation of strongly correlated phases with long-range interactions. For each of these subjects, the objectives are at the cutting edge of fundamental atomic and molecular science and technology.

1 496 400 €

Start date: 2013-02-01, End date: 2018-01-31

The Large Hadron Collider (LHC) at CERN collides protons at the highest energies. With the large datasets from Run 2 and the further increase expected from Run 3, the precision of LHC measurements will significantly improve over the next years. Color-free processes (for which the final state of the hard interaction is color neutral) are of central importance to several high-priority areas of the LHC precision physics program. Prominent examples are measurements of the W-boson mass, of the couplings of the Higgs boson, and searches for the elusive dark matter particles. The key innovation of COLORFREE will be to combine many different color-free processes in a new type of global analysis in which the dominant theory uncertainties are either eliminated or constrained by the data itself, thereby improving the theoretical precision up to an order of magnitude to the 1-2% level. In doing so, COLORFREE will unlock the full potential of existing and future precision measurements of color-free processes. This will be achieved 1) by exploiting and further developing a groundbreaking new method to reliably quantify perturbative theory uncertainties and their correlations, which was recently developed by the PI, and 2) by developing innovative new effective-field theory methods to account for all effects that are relevant at this precision but have been neglected so far. Important outcomes of COLORFREE will be: 1) Determinations of fundamental parameters at the highest possible precision, and stringent tests for possible effects beyond the Standard Model. 2) A new type of precision theory predictions with built-in uncertainties and correlations, which will solve a long-standing problem at the interface of theory and experiment. In particular, precision measurements often avoid theory limitations by relying on theory uncertainties to cancel between different control and signal regions, but until now have had no means to reliably quantify the remaining theory uncertainties.

2 000 000 €

Start date: 2021-10-01, End date: 2026-09-30

"Wave propagation in complex (disordered) media stretches our knowledge to the limit in many different fields of physics. It has important applications in seismology, acoustics, radar, and condensed matter. It is a problem of large fundamental interest, notably for the study of Anderson localization. In optics, it is of great importance in photonic devices, such as photonic crystals, plasmonic structures or random lasers. It is also at the heart of many biomedical-imaging issues: scattering ultimately limits the depth and resolution of all imaging techniques. We have recently demonstrated that wavefront shaping –i.e. adaptive optics applied to complex media- is the tool of choice to match and address the huge complexity of this problem in optics. The COMEDIA project aims at developing a novel wavefront shaping toolbox, addressing both spatial and spectral degrees of freedom of light. Thanks to this toolbox, we plan to fulfill the following objectives: 1) A full spatiotemporal control of the optical field in a complex environment, 2) Breakthrough results in imaging and nano-optics, 3) Original answers to some of the most intriguing fundamental questions in mesoscopic physics."

1 497 000 €

Start date: 2011-11-01, End date: 2016-10-31

In a quantum engineering approach we aim to create strongly correlated molecular quantum gases for polar molecules confined in an optical lattice to two-dimensional geometry with full quantum control of all de-grees of freedom with single molecule control and detection. The goal is to synthesize a high-fidelity molec-ular quantum simulator with thousands of particles and to carry out experiments on phases and dynamics of strongly-correlated quantum matter in view of strong long-range dipolar interactions. Our choice of mole-cule is the KCs dimer, which can either be a boson or a fermion, allowing us to prepare and probe bosonic as well as fermionic dipolar quantum matter in two dimensions. Techniques such as quantum-gas microscopy, perfectly suited for two-dimensional systems, will be applied to the molecular samples for local control and local readout. The low-entropy molecular samples are created out of quantum degenerate atomic samples by well-established coherent atom paring and coherent optical ground-state transfer techniques. Crucial to this pro-posal is the full control over the molecular sample. To achieve near-unity lattice filling fraction for the mo-lecular samples, we create two-dimensional samples of K-Cs atom pairs as precursors to molecule formation by merging parallel planar systems of K and Cs, which are either in a band-insulating state (for the fermions) or in Mott-insulating state (for the bosons), along the out-of-plane direction. The polar molecular samples are used to perform quantum simulations on ground-state properties and dy-namical properties of quantum many-body spin systems. We aim to create novel forms of superfluidity, to investigate into novel quantum many-body phases in the lattice that arise from the long-range molecular dipole-dipole interaction, and to probe quantum magnetism and its dynamics such as spin transport with single-spin control and readout. In addition, disorder can be engineered to mimic real physical situations.

2 356 117 €

Start date: 2019-01-01, End date: 2023-12-31

At different scales, from molecular systems to technological infrastructures, physical systems group in structures which are neither simply regular or random, but can be represented by networks with complex shape. Proteins in metabolic structures and the World Wide Web, for example, share the same kind of statistical distribution of connections of their constituents. In addition, the individual elements of natural samples, like atoms or electrons, are quantum objects. Hence replicating complex networks in a scalable quantum platform is a formidable opportunity to learn more about the intrinsic quantumness of real world and for the efficient exploitation of quantum-complex structures in future technologies. Future trusted large-scale communications and efficient big data handling, in fact, will depend on at least one of the two aspects -quantum or complex- of scalable systems, or on an appropriate combination of the two. In COQCOoN I will tackle both the quantum and the complex structure of physical systems. I will implement large quantum complex networks via multimode quantum systems based on both temporal and frequency modes of parametric processes pumped by pulsed lasers. Quantum correlations between amplitude and phase continuous variables will be arranged in complex topologies and delocalized single and multiple photon excitations will be distributed in the network. I aim at: -Learn from nature: I will reproduce complex topologies in the quantum network to query the quantum properties of natural processes, like energy transport and synchronization, and investigate how nature-inspired efficient strategies can be transferred in quantum technologies. -Control large quantum architectures: I will experiment network topologies that make quantum communication and information protocols resilient against internal failures and environmental changes. I will setup distant multi-party quantum communications and quantum simulation in complex networks.

1 990 000 €

Start date: 2019-06-01, End date: 2024-11-30

The Large Hadron Collider (LHC), a 7 + 7 TeV proton-proton collider under completion at CERN, the European Laboratory for Particle Physics in Geneva, will take experiments into a new energy domain beyond the Standard Model of strong and electroweak interactions. As the LHC will unveil the mysteries of the electroweak symmetry breaking, this will also have far-reaching implications for cosmology. The aim of this project is to work out what we may learn about the Early Universe from discoveries at the LHC. This concerns in particular the two fundamental questions of the nature of the Dark Matter and the origin of the matter-antimatter asymmetry of the Universe. The LHC-Cosmology interplay has been a topic of active research in the last years. However, studies have essentially focussed on a single class of models: supersymmetry. The original and innovative directions of this project are: 1) To investigate dark matter particle physics models that have not been explored yet and confront theoretical predictions with existing and upcoming observational constraints. Measuring the properties of the dark matter will require a complementarity between the LHC searches and the other numerous ongoing dark matter experiments such as gamma ray telescopes, neutrino telescopes, cosmic positron detectors ... etc. 2) To work out the details of the electroweak phase transition in extensions of the Standard Model. One of the best-motivated mechanism for generating the baryon asymmetry of the universe relies on a first-order electroweak phase transition. Interestingly, this has strong implications for Gravity Wave physics. We will explore thoroughly how the planned gravity wave detector and space interferometer LISA, which turns out to be a completely independent window on the electroweak scale, could complement the information provided by the LHC. This project will also serve as a solid basis for future research at the Internatinal electron-positron Linear Collider.

800 000 €

Start date: 2008-07-01, End date: 2013-06-30

The advent of high-power laser systems in the past two decades has opened a new field of research where astrophysical environments can be scaled down to laboratory dimensions, yet preserving the essential physics. This is due to the invariance of the equations of ideal magneto-hydrodynamics (MHD) to a class of self-similar transformations. In this proposal, we will apply these scaling laws to investigate the dynamics of the high Mach number shocks arising during the formation of the large-scale structure of the Universe. Although at the beginning of cosmic evolution matter was nearly homogenously distributed, today, as a result of gravitational instability, it forms a web-like structure made of filaments and clusters. Gas continues to accrete supersonically onto these collapsed structures, thus producing high Mach number shocks. It has been recently proposed that generation of magnetic fields can occur at these cosmic shocks on a cosmologically fast timescale via a Weibel-like instability, thus providing an appealing explanation to the ubiquitous magnetization of the Universe. Our proposal will thus provide the first experimental evidence of such mechanisms. We plan to measure the self-generated magnetic fields from laboratory shock waves using a novel combination of electron deflectometry, Faraday rotation measurements using THz lasers, and dB/dt probes. The proposed investigation on the generation of magnetic fields at shocks via plasma instabilities bears important general consequences. First, it will shed light on the origin of cosmic magnetic fields. Second, it would have a tremendous impact on one of the greatest puzzles of high energy astrophysics, the origin of Ultra High Energy Cosmic Rays. We plan to assess the role of charged particle acceleration via collisionless shocks in the amplification of the magnetic field as well as measure the spectrum of such accelerated particles. The experimental work will be carried both at Oxford U and at laser facilities.

1 119 690 €

Start date: 2010-12-01, End date: 2015-11-30

"A measurement of the 2S-2P transition frequencies (Lamb shift) in the muonic helium-3 and 4 ions by means of laser spectroscopy is proposed. This will lead to a ten times more accurate determination of the root-mean-square (rms) charge radii of the He-3 and He-4 nuclei. The radius of the magnetic moment distribution inside the He-3 nucleus will result from the hyperfine structure in muonic 3He. In the muonic helium ion, a single negative muon orbits the helium nucleus. The muon is a point-like lepton, just as the electron, except it is about 200 times heavier. This gives a factor of 200^3 = 10^7 enhancement of nuclear finite size effects on the energy levels of muonic vs. regular (electonic) Helium ions. Muonic helium is the ideal sytem to study the He nuclear size. The CREMA project has four main aims: (1) Solve the ""proton size puzzle"" created by our recently completed muonic hydrogen project [R. Pohl et al., ""The size of the proton"", Nature 466, 213 (2010)]. Our tenfold improvement of the proton charge radius resulted in a five sigma discrepancy with the 2006 CODATA value, which is mostly based on hydrogen spectroscopy. This poses a serious challenge to bound-state QED, and may even point towards new physics. CREMA will help to clarify this. (2) Absolute nuclear charge radii of all helium isotopes He-3,4,6,8 will result from CREMA. The charge radius differences are precisely known, but the absolute size of the He-4 anchor nucleus can best be measured in muonic helium. Absolute charge radii are a more stringent benchmark for few-nucleon nuclear models than the radius difference. (3) Test of bound-state QED: Spectroscopy of regular He+ ions is underway. He+ (Z=2) is more sensitive than hydrogen (Z=1) to higher-order QED contributions which scale as Z^5. An accurate He charge radius from CREMA is mandatory for this. (4) An improved value of the Rydberg constant will result from the He+ spectroscopy only with the improved charge radius from CREMA."

1 499 976 €

Start date: 2011-11-01, End date: 2016-10-31

Low temperature matter exhibits a spectacular variety of highly ordered states that occur through phase transitions. In quantum systems, phase transitions and associated critical phenomena constitute a central issue of modern physics. Wilson’s theory of renormalization showed that very different physical systems could be unified under the same universality class characterized by critical exponents. The high degree of control offered by ultracold atom experiments sets them as an ideal platform for the investigation of phase transitions and critical phenomena. CRITISUP2 aims at exploring criticality in superfluid spin ½ Fermi gases where the interplay between temperature spin polarization and interactions is at the origin of a rich phase diagram and a variety of phase transitions. We will measure the corresponding static and dynamic critical exponents, and search for the long-sought Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase predicted over 50 years ago. We will also study the phase diagram and critical counterflow of dual Bose-Fermi superfluids which have emerged as a new paradigm of quantum matter. Cutting-edge Bold Diagrammatic Monte Carlo and new resummation methods, developed in-house, will be confronted to the experiments on the one hand, and provide answers to debated questions on the other. The expected outcomes of CRITISUP2 will constitute a major leap forward relevant for several fields of modern physics, ranging from condensed-matter to astrophysics, nuclear physics, and high energy physics.

2 246 536 €

Start date: 2017-05-01, End date: 2022-04-30

A new generation of parasitic beam extraction of high energy particles from an accelerator is proposed in CRYSBEAM. Instead of massive magnetic kickers, bent thin crystals trapping particles within the crystal lattice planes are used. This type of beam manipulation opens new fields of investigation of fundamental interactions between particles and of coherent interactions between particles and matter. An experiment in connection to Ultra High Energy Cosmic Rays study in Earth’s high atmosphere can be conducted. Several TeV energy protons or ions are deflected towards a chosen target by the bent lattice planes only when the lattice planes are parallel to the incoming particles direction. The three key ingredients of CRYSBEAM are: - a goniometer based on piezoelectric devices that orients a bent finely-polished low-miscut silicon crystal with a high resolution and repeatability, monitoring its position with synthetic diamond sensors. Novel procedures in crystal manufacturing & testing and cutting-edge mechanical solutions for motion technology in vacuum are developed; - a silica screen that measures the deflected particles via Cherenkov radiation emission in micrometric optical waveguides. These are obtained with an ultra-short laser micro-machining technique as for photonic devices used in quantum optics and quantum computing. The screen is a direct beam-imaging detector for a high radiation dose environment; - a smart absorber, which simulates the Earth’s atmosphere, where particles are smashed and secondary showers are initiated. This sets the path to measure hadronic cross sections at an energy relevant for cosmic rays investigation. The R&D for the various components of such a system are carried out within this project and direct tests at CERN Super Proton Synchrotron to be performed prior to the final installation in the Large Hadron Collider at CERN are proposed. A new concept of particle accelerator operations will be finally set in place.

1 989 746 €

Start date: 2014-05-01, End date: 2019-04-30

Quantum field theory provides a theoretical framework to explain quantitatively natural phenomena as diverse as the fluctuations in the cosmic microwave background, superconductivity, and elementary particle interactions in colliders. Even if we use quantum field theories in different settings, their structure and dynamics are still largely mysterious. Weakly coupled systems can be studied perturbatively, however many natural phenomena are characterized by strong self-interactions (e.g. high T superconductors, nuclear forces) and their analysis requires going beyond perturbation theory. Supersymmetric field theories are very interesting in this respect because they can be studied exactly even at strong coupling and their dynamics displays phenomena like confinement or the breaking of chiral symmetries that occur in nature and are very difficult to study analytically. Recently it was realized that many interesting insights on the dynamics of supersymmetric field theories can be obtained by placing these theories in curved space preserving supersymmetry. These advances have opened new research avenues but also left many important questions unanswered. The aim of our research programme will be to clarify the dynamics of supersymmetric field theories in curved space and use this knowledge to establish new exact results for strongly coupled supersymmetric gauge theories. The novelty of our approach resides in the systematic use of the interplay between the physical properties of a supersymmetric theory and the geometrical properties of the space-time it lives in. The analytical results we will obtain, while derived for very symmetric theories, can be used as a guide in understanding the dynamics of many physical systems. Besides providing new tools to address the dynamics of quantum field theory at strong coupling this line of investigation could lead to new connections between Physics and Mathematics.

1 145 879 €

Start date: 2015-09-01, End date: 2020-08-31

The past decade saw a remarkable progress in the development of attosecond technologies based on the use of intense few-cycle optical pulses. The control over the underlying single-cycle phenomena, such as the higher-order harmonic generation by an ionized and subsequently re-scattered electronic wave packet, has become routine once the carrier-envelope phase (CEP) of an amplified laser pulse was stabilized, opening the way to maintain the shot-to-shot reproducible pulse electric field. Drawing on a mix of several laser technologies and phase-control concepts, this proposal aims to take strong-field optical tools to a conceptually new level: from adjusting the intensity and timing of a principal half-cycle to achieving a full-fledged multicolor Fourier synthesis of the optical cycle dynamics by controlling a multi-dimensional space of carrier frequencies, relative, and absolute phases. The applicant and his team, through their unique expertise in the CEP control and optical amplification methods, are currently best positioned to pioneer the development of an optical programmable “attosecond optical shaper” and attain the relevant multicolor pulse intensity levels of PW/cm2. This will enable an immediate pursuit of several exciting strong-field applications that can be jump-started by the emergence of a technique for the fully-controlled cycle sculpting and would rely on the relevant experimental capabilities already established in the applicant’s emerging group. We show that even the simplest form of an incommensurate-frequency synthesizer can potentially solve the long-standing debate on the mechanism of strong-field rectification. More advanced waveforms will be employed to dramatically enhance coherent X ray yield, trace the time profile of attosecond ionization in transparent bulk solids, and potentially control the result of molecular dissociation by influencing electronic coherences in polyatomic molecules.

980 000 €

Start date: 2012-01-01, End date: 2015-06-30