ERC FUNDED PROJECTS

One of the major challenges in theoretical physics is the development of systematic methods for describing and simulating quantum many body systems with strong interactions. Given the huge experimental progress and technological potential in manipulating strongly correlated atoms and electrons, there is a pressing need for such a better theory. The study of quantum entanglement holds the promise of being a game changer for this question. By mapping out the entanglement structure of the low-energy wavefunctions of quantum spin systems on the lattice, the prototypical example of strongly correlated systems, we have found that the associated wavefunctions can be very well modeled by a novel class of variational wavefunctions, called tensor network states. Tensor networks are changing the ways in which strongly correlated systems can be simulated, classified and understood: as opposed to the usual many body methods, these tensor networks are generic and describe non-perturbative effects in a very natural way. The goal of this proposal is to advance the scope and use of tensor networks in several directions, both from the numerical and theoretical point of view. We plan to study the differential geometric character of the manifold of tensor network states and the associated nonlinear differential equations of motion on it, develop post tensor network methods in the form of effective theories on top of the tensor network vacuum, study tensor networks in the context of lattice gauge theories and topologically ordered systems, and investigate the novel insights that tensor networks are providing to the renormalization group and the holographic principle. Colloquially, we believe that tensor networks and the theory of entanglement provide a basic new vocabulary for describing strongly correlated quantum systems, and the main goal of this proposal is to develop the syntax and semantics of that new language.

1 927 500 €

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

Concrete production processes do not take full advantage of the rheological potential of fresh cementitious materials, and are still largely labour-driven and sensitive to the human factor. SmartCast proposes a new concrete casting concept to transform the concrete industry into a highly automated technological industry. Currently, the rheological properties of the concrete are defined by mix design and mixing procedure without any further active adjustment during casting. The goal of this proposal is the active control of concrete rheology during casting, and the active triggering of early stiffening of the concrete as soon as it is put in place. The ground-breaking idea to achieve this goal, is to develop concrete with actively controllable rheology by adding admixtures responsive to externally activated electromagnetic frequencies. Inter-disciplinary insights are important to achieve these goals, including inputs from concrete technology, polymer science, electrochemistry, rheology and computational fluid dynamics. We will develop 4 new experimental test set-ups allowing to study active rheology control during different phases of the casting process: 1)concrete pumping (control of slip layer), 2)while flowing in the formwork (bulk control of rheology), 3)while flowing through formwork joints (control of formwork tightness), and 4)once the concrete is in its final position (trigger stiffening). Well-designed polymers with the desired response to the applied activation will be added to the concrete during mixing. The experiments will be analysed by advanced computational flow modelling based on fundamental rheological laws. Special attention will be paid to the compatibility of all responsive polymers selected for the different control phases. SmartCast will mean a paradigm shift for formwork-based concrete casting. The developed active rheology control will provide a fundamental basis for the development of future-proof 3D printing techniques in concrete industry

2 498 750 €

Start date: 2016-10-01, End date: 2021-09-30

SpecMAT aims at providing crucial experimental information to answer key questions about the structure of atomic nuclei: - What are the forces driving the shell structure in nuclei and how do they change in nuclei far from stability? - What remains of the Z = 28 and N = 50 “magic numbers” in 78Ni? - Do we understand shape coexistence in nuclei, and what are the mechanisms controlling its appearance? The position of natural and “intruder” shells will be mapped in two critical regions, the neutron-rich nuclei around Z = 28 and the neutron-deficient nuclei around Z = 82. The centroids of the shell strength are derived from the complete spectroscopy of those systems in nucleon-transfer measurements. This method will be applied for the first time in the region of neutron-deficient Pb nuclei. In SpecMAT (Spectroscopy of exotic nuclei in a Magnetic Active Target) a novel instrument will overcome the present challenges in performing such measurements with very weak beams of unstable nuclei. It combines high luminosity, high efficiency and a very large dynamic range and allows detection of both charged-particle and gamma-ray radiation. The instrument owns its remarkable performances to a number of advanced technologies concerning the use of electronics, gaseous detectors and gamma-ray detectors in a magnetic field. The SpecMAT detector will be coupled to the HIE-ISOLDE facility for the production and post-acceleration of radioactive ion beams in construction at CERN in Geneva. HIE-ISOLDE will provide world-unique beams thanks to the use of the proton injector of the CERN complex. If successful, SpecMAT at HIE-ISOLDE will produce specific results in nuclear structure which cannot be reached by other programmes elsewhere. Such results will have a significant impact on the present theories and models of the atomic nucleus.

1 944 900 €

Start date: 2014-06-01, End date: 2019-05-31

Fertilization is essential for a species to survive. Mammalian sexual reproduction requires the fusion between the haploid gametes sperm and egg to create a new diploid organism. Although fertilization has been studied for decades, and despite the remarkable recent discoveries of Izumo (on sperm) and Juno (on oocytes) as a critical ligand:receptor pair, due to the structure of Izumo and Juno, it is clear that other players on both the sperm and the oocytes must be involved. While the focus of our laboratory over the years has been in understanding apoptotic cell clearance by phagocytes, we accidentally noted that viable, motile, and fertilization-competent sperm exposes phosphatidylserine (PtdSer). PtdSer is a phospholipid normally exposed during apoptosis and functions as an ‘eat-me’ signal for phagocytosis. Further, masking this PtdSer on sperm inhibits fertilization in vitro. Based on additional exciting preliminary data, in this ERC proposal, we will test the hypothesis that PtdSer on viable sperm and the complementary PtdSer receptors on oocytes are key players in mammalian fertilization. We will test this at a molecular, biochemical, cellular, functional, and genetic level. From the sperm perspective — we will ask how does PtdSer changes during sperm maturation, and what molecular mechanisms regulate the exposure of PtdSer on viable sperm. From the oocyte perspective — we will test the genetic relevance of different PtdSer receptors in fertilization. From the PtdSer perspective — we will test PtdSer induces novel signals within oocytes. By combining the tools and knowledge from field of phagocytosis with tools from spermatogenesis/fertilization, this proposal integrates fields that normally do not intersect. In summary, we believe that these studies are innovative, timely, and will identify new players involved in mammalian fertilization. We expect the results of these studies to have high relevance to both male and female reproductive health and fertility.

2 499 375 €

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