ERC FUNDED PROJECTS

Wave-particle interactions are ubiquitous in nature and play a fundamental role in astrophysical and fusion plasmas. In solar plasmas, magnetohydrodynamic (MHD) fluctuations are thought to be responsible for the heating of the solar corona and the generation of the solar wind. In magnetically confined fusion (MCF) devices, enhanced particle transport induced by MHD fluctuations can deteriorate the plasma confinement, and also endanger the device integrity. MCF devices are an ideal testbed to verify current models and develop mitigation / protection techniques. The proposed project paves the way for providing active control techniques to tame the MHD induced particle transport in a fusion plasma. A solid understanding of the interaction between energetic particles and MHD instabilities in the presence of electric fields and plasma currents is required to develop such techniques. I will pursue this goal through innovative diagnosis techniques with unprecedented spatio-temporal resolution. Combined with state-of-the-art hybrid MHD codes, a deep insight into the underlying physics mechanism will be gained. The outcome of this research project will have a major impact for next-step MCF devices as I will provide ground-breaking control techniques for mitigating MHD induced particle transport in magnetized plasmas. The project consists of 3 research lines which follow a bottom-up approach: (1) Cutting-edge instrumentation, aiming at the new generation of energetic particle and edge current diagnostics. (2) Unravel the dynamics of energetic particles, electric fields, edge currents and MHD fluctuations. (3) From lab to space weather: The developed models will revolutionize our understanding of the observed particle acceleration and transport in the solar corona. Based on this approach, the project represents a gateway between the fusion, astrophysics and space communities opening new avenues for a common basic understanding.

1 512 250 €

Start date: 2019-05-01, End date: 2024-04-30

We propose to elucidate the structural design principles of naturally occurring antibody complementarity-determining regions (CDRs) and to computationally design novel antibody functions. Antibodies represent the most versatile known system for molecular recognition. Research has yielded many insights into antibody design principles and promising biotechnological and pharmaceutical applications. Still, our understanding of how CDRs encode specific loop conformations lags far behind our understanding of structure-function relationships in non-immunological scaffolds. Thus, design of antibodies from first principles has not been demonstrated. We propose a computational-experimental strategy to address this challenge. We will: (a) characterize the design principles and sequence elements that rigidify antibody CDRs. Natural antibody loops will be subjected to computational modeling, crystallography, and a combined in vitro evolution and deep-sequencing approach to isolate sequence features that rigidify loop backbones; (b) develop a novel computational-design strategy, which uses the >1000 solved structures of antibodies deposited in structure databases to realistically model CDRs and design them to recognize proteins that have not been co-crystallized with antibodies. For example, we will design novel antibodies targeting insulin, for which clinically useful diagnostics are needed. By accessing much larger sequence/structure spaces than are available to natural immune-system repertoires and experimental methods, computational antibody design could produce higher-specificity and higher-affinity binders, even to challenging targets; and (c) develop new strategies to program conformational change in CDRs, generating, e.g., the first allosteric antibodies. These will allow targeting, in principle, of any molecule, potentially revolutionizing how antibodies are generated for research and medicine, providing new insights on the design principles of protein functional sites.

1 499 930 €

Start date: 2013-09-01, End date: 2018-08-31

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