ERC FUNDED PROJECTS

Correlated electrons are at the forefront of condensed matter theory. Interacting quasi-1D electrons have seen vast progress in analytical and numerical theory, and thus in fundamental understanding and quantitative prediction. Yet, in the 1D limit fluctuations preclude important technological use, particularly of superconductors. In contrast, high-Tc superconductors in 2D/3D are not precluded by fluctuations, but lack a fundamental theory, making prediction and engineering of their properties, a major goal in physics, very difficult. This project aims to combine the advantages of both areas by making major progress in the theory of quasi-1D electrons coupled to an electron bath, in part building on recent breakthroughs (with the PIs extensive involvement) in simulating 1D and 2D electrons with parallelized density matrix renormalization group (pDMRG) numerics. Such theory will fundamentally advance the study of open electron systems, and show how to use 1D materials as elements of new superconducting (SC) devices and materials: 1) It will enable a new state of matter, 1D electrons with true SC order. Fluctuations from the electronic liquid, such as graphene, could also enable nanoscale wires to appear SC at high temperatures. 2) A new approach for the deliberate engineering of a high-Tc superconductor. In 1D, how electrons pair by repulsive interactions is understood and can be predicted. Stabilization by reservoir - formed by a parallel array of many such 1D systems - offers a superconductor for which all factors setting Tc are known and can be optimized. 3) Many existing superconductors with repulsive electron pairing, all presently not understood, can be cast as 1D electrons coupled to a bath. Developing chain-DMFT theory based on pDMRG will allow these materials SC properties to be simulated and understood for the first time. 4) The insights gained will be translated to 2D superconductors to study how they could be enhanced by contact with electronic liquids.

1 491 013 €

Start date: 2018-10-01, End date: 2023-09-30

The goal of 2D-TOPSENSE is to exploit the remarkable stretchability of two-dimensional semiconductors to fabricate optoelectronic devices where strain is used as an external knob to tune their properties. While bulk semiconductors tend to break under strains larger than 1.5%, 2D semiconductors (such as MoS2) can withstand deformations of up to 10-20% before rupture. This large breaking strength promises a great potential of 2D semiconductors as ‘straintronic’ materials, whose properties can be adjusted by applying a deformation to their lattice. In fact, recent theoretical works predicted an interesting physical phenomenon: a tensile strain-induced semiconductor-to-metal transition in 2D semiconductors. By tensioning single-layer MoS2 from 0% up to 10%, its electronic band structure is expected to undergo a continuous transition from a wide direct band-gap of 1.8 eV to a metallic behavior. This unprecedented large strain-tunability will undoubtedly have a strong impact in a wide range of optoelectronic applications such as photodetectors whose cut-off wavelength is tuned by varying the applied strain or atomically thin light modulators. To date, experimental works on strain engineering have been mostly focused on fundamental studies, demonstrating part of the potential of 2D semiconductors in straintronics, but they have failed to exploit strain engineering to add extra functionalities to optoelectronic devices. In 2D-TOPSENSE I will go beyond the state of the art in straintronics by designing and fabricating optoelectronic devices whose properties and performance can be tuned by means of applying strain. 2D-TOPSENSE will focus on photodetectors with a tunable bandwidth and detectivity, light emitting devices whose emission wavelength can be adjusted, light modulators based on 2D semiconductors such as transition metal dichalcogenides or black phosphorus and solar funnels capable of directing the photogenerated charge carriers towards a specific position.

1 930 437 €

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

Ubiquitous in nature, light-matter interactions are of fundamental importance in science and all optical technologies. Understanding and controlling them has been a long-pursued objective in modern physics. However, so far, related experiments have relied on traditional optical schemes where, owing to the classical diffraction limit, control of optical fields to length scales below the wavelength of light is prevented. Importantly, this limitation impedes to exploit the extraordinary fundamental and scaling potentials of nanoscience and nanotechnology. A solution to concentrate optical fields into sub-diffracting volumes is the excitation of surface polaritons –coupled excitations of photons and mobile/bound charges in metals/polar materials (plasmons/phonons)-. However, their initial promises have been hindered by either strong optical losses or lack of electrical control in metals, and difficulties to fabricate high optical quality nanostructures in polar materials. With the advent of two-dimensional (2D) materials and their extraordinary optical properties, during the last 2-3 years the visualization of both low-loss and electrically tunable (active) plasmons in graphene and high optical quality phonons in monolayer and multilayer h-BN nanostructures have been demonstrated in the mid-infrared spectral range, thus introducing a very encouraging arena for scientifically ground-breaking discoveries in nano-optics. Inspired by these extraordinary prospects, this ERC project aims to make use of our knowledge and unique expertise in 2D nanoplasmonics, and the recent advances in nanophononics, to establish a technological platform that, including coherent sources, waveguides, routers, and efficient detectors, permits an unprecedented active control and manipulation (at room temperature) of light and light-matter interactions on the nanoscale, thus laying experimentally the foundations of a 2D nano-optics field.

1 459 219 €

Start date: 2017-01-01, End date: 2021-12-31

Design of new thermoelectric devices based on layered and field modulated nanostructures of strongly correlated electron systems

1 427 190 €

Start date: 2010-11-01, End date: 2015-10-31

Computational Electromagnetics (CEM) is the scientific field at the origin of all new modeling and simulation tools required by the constantly arising design challenges of emerging and future technologies in applied electromagnetics. As in many other technological fields, however, the trend in all emerging technologies in electromagnetic engineering is going towards miniaturized, higher density and multi-scale scenarios. Computationally speaking this translates in the steep increase of the number of degrees of freedom. Given that the design cost (the cost of a multi-right-hand side problem dominated by matrix inversion) can scale as badly as cubically with these degrees of freedom, this fact, as pointed out by many, will sensibly compromise the practical impact of CEM on future and emerging technologies. For this reason, the CEM scientific community has been looking for years for a FFT-like paradigm shift: a dynamic fast direct solver providing a design cost that would scale only linearly with the degrees of freedom. Such a fast solver is considered today a Holy Grail of the discipline. The Grand Challenge of 321 will be to tackle this Holy Grail in Computational Electromagnetics by investigating a dynamic Fast Direct Solver for Maxwell Problems that would run in a linear-instead-of-cubic complexity for an arbitrary number and configuration of degrees of freedom. The failure of all previous attempts will be overcome by a game-changing transformation of the CEM classical problem that will leverage on a recent breakthrough of the PI. Starting from this, the project will investigate an entire new paradigm for impacting algorithms to achieve this grand challenge. The impact of the FFT’s quadratic-to-linear paradigm shift shows how computational complexity reductions can be groundbreaking on applications. The cubic-to-linear paradigm shift, which the 321 project will aim for, will have such a rupturing impact on electromagnetic science and technology.

2 000 000 €

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

The realization of high-performance micro-supercapacitors is currently a big challenge but the ineluctable applications requiring such miniaturized energy storage devices are continuously emerging, from wearable electronic gadgets to wireless sensor networks. Although they store less energy than micro-batteries, micro-supercapacitors can be charged and discharged very rapidly and exhibit a quasi-unlimited lifetime. The global scientific research is consequently largely focused on the improvement of their capacitance and energetic performances. However, to date, they are still far from being able to power sensors or electronic components. Here I propose a 3D paradigm shift of micro-supercapacitor design to ensure increased energy storage capacities. Hydrous ruthenium dioxide (RuO2) is a pseudocapacitive material for supercapacitor electrode well-known for its high capacitance. A thin-film of ruthenium will be deposited by atomic layer deposition (ALD), followed by an electrochemical oxidation process, onto a high-surface-area 3D current collector prepared via an ingenious dynamic template built with hydrogen bubbles. The structural features of these 3D architectures will be controllably tailored by the processing methodologies. These electrodes will be combined with an innovative electrolyte in solid form (a protic ionogel) able to operate over an extended cell voltage. In a parallel investigation, we will develop a fundamental understanding of electrochemical reactions occurring at the nanoscale with a FIB-patterned (Focused Ion Beam) RuO2 nano-supercapacitor. The resulting 3D micro-supercapacitors should display extremely high power, long lifetime and – for the first time – energy densities competing or even exceeding that of micro-batteries. As a key achievement, prototypes will be designed using a new concept based on a self-adaptative micro-supercapacitors matrix, which arranges itself according to the global amount of energy stored.

1 673 438 €

Start date: 2018-04-01, End date: 2023-03-31

Label-free optical nanoscopy, free from photobleaching and photochemical toxicity of fluorescence labels and yielding 3D morphological resolution of <50 nm, is the future of live cell imaging. 3D-nanoMorph breaks the diffraction barrier and shifts the paradigm in label-free nanoscopy, providing isotropic 3D resolution of <50 nm. To achieve this, 3D-nanoMorph performs non-linear inverse scattering for the first time in nanoscopy and decodes scattering between sub-cellular structures (organelles). 3D-nanoMorph innovatively devises complementary roles of light measurement system and computational nanoscopy algorithm. A novel illumination system and a novel light collection system together enable measurement of only the most relevant intensity component and create a fresh perspective about label-free measurements. A new computational nanoscopy approach employs non-linear inverse scattering. Harnessing non-linear inverse scattering for resolution enhancement in nanoscopy opens new possibilities in label-free 3D nanoscopy. I will apply 3D-nanoMorph to study organelle degradation (autophagy) in live cancer cells over extended duration with high spatial and temporal resolution, presently limited by the lack of high-resolution label-free 3D morphological nanoscopy. Successful 3D mapping of nanoscale biological process of autophagy will open new avenues for cancer treatment and showcase 3D-nanoMorph for wider applications. My cross-disciplinary expertise of 14 years spanning inverse problems, electromagnetism, optical microscopy, integrated optics and live cell nanoscopy paves path for successful implementation of 3D-nanoMorph.

1 499 999 €

Start date: 2019-07-01, End date: 2024-06-30

Faithful repair of double stranded DNA breaks (DSBs) is essential, as they are at the origin of genome instability, chromosomal translocations and cancer. Cells repair DSBs through different pathways, which can be faithful or mutagenic, and the balance between them at a given locus must be tightly regulated to preserve genome integrity. Although, much is known about DSB repair factors, how the choice between pathways is controlled within the nuclear environment is not understood. We have shown that nuclear architecture and non-random genome organization determine the frequency of chromosomal translocations and that pathway choice is dictated by the spatial organization of DNA in the nucleus. Nevertheless, what determines which pathway is activated in response to DSBs at specific genomic locations is not understood. Furthermore, the impact of 3D-genome folding on the kinetics and efficiency of DSB repair is completely unknown. Here we aim to understand how nuclear compartmentalization, chromatin structure and genome organization impact on the efficiency of detection, signaling and repair of DSBs. We will unravel what determines the DNA repair specificity within distinct nuclear compartments using protein tethering, promiscuous biotinylation and quantitative proteomics. We will determine how DNA repair is orchestrated at different heterochromatin structures using a CRISPR/Cas9-based system that allows, for the first time robust induction of DSBs at specific heterochromatin compartments. Finally, we will investigate the role of 3D-genome folding in the kinetics of DNA repair and pathway choice using single nucleotide resolution DSB-mapping coupled to 3D-topological maps. This proposal has significant implications for understanding the mechanisms controlling DNA repair within the nuclear environment and will reveal the regions of the genome that are susceptible to genomic instability and help us understand why certain mutations and translocations are recurrent in cancer

1 999 750 €

Start date: 2017-03-01, End date: 2022-02-28

All properties of matter are ultimately governed by the forces between single atoms, but our knowledge of interatomic, and intermolecular, potentials is often derived indirectly. In 3DMOSHBOND, I outline a program of work designed to create a paradigm shift in the direct measurement of complex interatomic potentials via a fundamental reimagining of how atomic resolution imaging, and force measurement, techniques are applied. To provide a clear proof of principle demonstration of the power of this concept, I propose to map the strength, shape and extent of single hydrogen bonding (H-bonding) interactions in 3D with sub-Angstrom precision. H-bonding is a key component governing intermolecular interactions, particularly for biologically important molecules. Despite its critical importance, H-bonding is relatively poorly understood, and the IUPAC definition of the H-bond was changed as recently as 2011- highlighting the relevance of a new means to engage with these fundamental interactions. Hitherto unprecedented resolution and accuracy will be achieved via a creation of a novel layer of vertically oriented H-bonding molecules, functionalisation of the tip of a scanning probe microscope with a single complementary H-bonding molecule, and by complete characterisation of the position of all atoms in the junction. This will place two H-bonding groups “end on” and map the extent, and magnitude, of the H-bond with sub-Angstrom precision for a variety of systems. This investigation of the H-bond will present us with an unparalleled level of information regarding its properties. Experimental results will be compared with ab initio density functional theory (DFT) simulations, to investigate the extent to which state-of-the-art simulations are able to reproduce the behaviour of the H-bonding interaction. The project will create a new generalised probe for the study of single atomic and molecular interactions.

1 971 468 €

Start date: 2018-01-01, End date: 2022-12-31