ERC FUNDED PROJECTS

"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

Two-dimensional transition metal dichalcogenides (2D-TMDs) are an exciting class of new materials. Their ultrathin body, optical band gap and unusual spin and valley polarization physics make them very promising candidates for a vast new range of (opto-)electronic applications. So far, most experimental work on 2D-TMDs has been performed on exfoliated flakes made by the ‘Scotch tape’ technique. The major next challenge is the large-area synthesis of 2D-TMDs by a technique that ultimately can be used for commercial device fabrication. Building upon pure 2D-TMDs, even more functionalities can be gained from 2D-TMD alloys and heterostructures. Theoretical work on these derivates reveals exciting new phenomena, but experimentally this field is largely unexplored due to synthesis technique limitations. The goal of this proposal is to combine atomic layer deposition with plasma chemistry to create a novel surface-controlled, industry-compatible synthesis technique that will make large area 2D-TMDs, 2D-TMD alloys and 2D-TMD heterostructures a reality. This innovative approach will enable systematic layer dependent studies, likely revealing exciting new properties, and provide integration pathways for a multitude of applications. Atomistic simulations will guide the process development and, together with in- and ex-situ analysis, increase the understanding of the surface chemistry involved. State-of-the-art high resolution transmission electron microscopy will be used to study the alloying process and the formation of heterostructures. Luminescence spectroscopy and electrical characterization will reveal the potential of the synthesized materials for (opto)-electronic applications. The synergy between the excellent background of the PI in 2D materials for nanoelectronics and the group’s leading expertise in ALD and plasma science is unique and provides an ideal stepping stone to develop the synthesis of large-area 2D-TMDs and derivatives.

1 968 709 €

Start date: 2015-08-01, End date: 2020-12-31

Carbon dioxide capture and storage is a technology to mitigate climate change by removing CO2 from flue gas streams or the atmosphere and storing it in geological formations. While CO2 removal from natural gas by amine scrubbing is implemented on the large scale, the cost of such process is currently prohibitively expensive. Inexpensive alkali earth metal oxides (MgO and CaO) feature high theoretical CO2 uptakes, but suffer from poor cyclic stability and slow kinetics. Yet, the key objective of recent research on alkali earth metal oxide based CO2 sorbents has been the processing of inexpensive, naturally occurring CO2 sorbents, notably limestone and dolomite, to stabilize their modest CO2 uptake and to establish re-activation methods through engineering approaches. While this research demonstrated a landmark Megawatt (MW) scale viability of the process, our fundamental understanding of the underlying CO2 capture, regeneration and deactivation pathways did not improve. The latter knowledge is, however, vital for the rational design of improved, yet practical CaO and MgO sorbents. Hence this proposal is concerned with obtaining an understanding of the underlying mechanisms that control the ability of an alkali metal oxide to capture a large quantity of CO2 with a high rate, to regenerate and to operate with high cyclic stability. Achieving these aims relies on the ability to fabricate model structures and to characterize in great detail their surface chemistry, morphology, chemical composition and changes therein under reactive conditions. This makes the development of operando and in situ characterization tools an essential prerequisite. Advances in these areas shall allow achieving the overall goal of this project, viz. to formulate a roadmap to fabricate improved CO2 sorbents through their precisely engineered structure, composition and morphology.

1 994 900 €

Start date: 2019-06-01, End date: 2024-05-31

Applied electrochemistry plays a key role in many technologies, such as batteries, fuel cells, supercapacitors or solar cells. It is therefore at the core of many research programs all over the world. Yet, fundamental electrochemical investigations remain scarce. In particular, electrochemistry is among the fields for which the gap between theory and experiment is the largest. From the computational point of view, there is no molecular dynamics (MD) software devoted to the simulation of electrochemical systems while other fields such as biochemistry (GROMACS) or material science (LAMMPS) have dedicated tools. This is due to the difficulty of accounting for complex effects arising from (i) the degree of metallicity of the electrode (i.e. from semimetals to perfect conductors), (ii) the mutual polarization occurring at the electrode/electrolyte interface and (iii) the redox reactivity through explicit electron transfers. Current understanding therefore relies on standard theories that derive from an inaccurate molecular-scale picture. My objective is to fill this gap by introducing a whole set of new methods for simulating electrochemical systems. They will be provided to the computational electrochemistry community as a cutting-edge MD software adapted to supercomputers. First applications will aim at the discovery of new electrolytes for energy storage. Here I will focus on (1) ‘‘water-in-salts’’ to understand why these revolutionary liquids enable much higher voltage than conventional solutions (2) redox reactions inside a nanoporous electrode to support the development of future capacitive energy storage devices. These selected applications are timely and rely on collaborations with leading experimental partners. The results are expected to shed an unprecedented light on the importance of polarization effects on the structure and the reactivity of electrode/electrolyte interfaces, establishing MD as a prominent tool for solving complex electrochemistry problems.

1 588 769 €

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

Molecular structure elucidation is of great importance in synthetic chemistry, pharmacy, life sciences, energy and environmental sciences, and technology applications. To date structure elucidation by atomic force microscopy (AFM) has been demonstrated for a few, small and mainly planar molecules. In this project high-risk, high-impact scientific questions will be solved using structure elucidation with the AFM employing a novel tool and novel methodologies. A combined low-temperature scanning tunneling microscope/atomic force microscope (LT-STM/AFM) with high throughput and in situ electrospray deposition method will be developed. Chemical resolution will be achieved by novel measurement techniques, in particular the usage of different and novel tip functionalizations and combination with Kelvin probe force microscopy. Elements will be identified using substructure recognition provided by a database that will be erected and by refined theory and simulations. The developed tools and techniques will be applied to molecules of increasing fragility, complexity, size, and three-dimensionality. In particular samples that are challenging to characterize with conventional methods will be studied. Complex molecular mixtures will be investigated molecule-by-molecule taking advantage of the single-molecule sensitivity. The absolute stereochemistry of molecules will be determined, resolving molecules with multiple stereocenters. The operation of single molecular machines as nanocars and molecular gears will be investigated. Reactive intermediates generated with atomic manipulation will be characterized and their on-surface reactivity will be studied by AFM.

2 000 000 €

Start date: 2016-06-01, End date: 2021-05-31

The aim of this project is to develop and to demonstrate a novel theoretical framework devoted to rationalizing the formulation of composite electrodes containing next-generation material chemistries for high energy density secondary batteries. The framework will be established through the combination of discrete particle and continuum mathematical models within a multiscale computational workflow integrating the individual models and mimicking the different steps along the electrode fabrication process, including slurry preparation, drying and calendering. Strongly complemented by dedicated experimental characterizations which are devoted to its validation, the goal of this framework is to provide insights about the impacts of material properties and fabrication process parameters on the electrode mesostructures and their corresponding correlation to the resulting electrochemical performance. It targets self-organization mechanisms of material mixtures in slurries by considering the interactions between the active and conductive materials, solvent, binders and dispersants and the relationship between the materials properties such as surface chemistry and wettability. Optimal electrode formulation, fabrication process and the arising electrode mesostructure can then be achieved. Additionally, the framework will be integrated into an online and open access infrastructure, allowing predictive direct and reverse engineering for optimized electrode designs to attain high quality electrochemical performances. Through the demonstration of a multidisciplinary, flexible and transferable framework, this project has tremendous potential to provide insights leading to proposals of new and highly efficient industrial techniques for the fabrication of cheaper and reliable next-generation secondary battery electrodes for a wide spectrum of applications, including Electric Transportation.

1 976 445 €

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

Strong-field-driven electric currents in condensed-matter systems open new frontiers in manipulating electronic and optical properties on petahertz frequency scales. In this regime, new challenges arise as the role of the band structure and the quantum nature of ultrafast electron-hole dynamics have yet to be resolved. While petahertz spectroscopy and control of condensed-matter systems holds great potential, revealing the underlying attosecond (1 attosecond – 10(-18) second) dynamics of electrons in solids is still in its infancy. The proposed research aims at the development of a state-of-the-art attosecond metrology scheme that integrates the concept of holography with attosecond gating. Attosecond-gated holography will provide direct insight into the instantaneous evolution of the complex quantum wavefunctions in solid-state systems. This scheme will enable us to follow the electron-hole wavepacket evolution during ultrafast band structure deformation, probing a range of fundamental processes – from sub-cycle phase transitions to ultrafast dynamics in correlated systems. In ATTO-GRAM, we will establish attosecond-gated holography and then apply it to study field-induced transient band structures, resolve electron-hole dynamics during lattice deformation and reveal attosecond phenomena in strongly correlated systems. Integrating state-of-the-art experimental schemes, supported by advanced theoretical analysis, will lead to the discoveries of new phenomena previously deemed inaccessible. The impact of the proposed research reaches beyond attosecond metrology – opening new routes in the establishment of compact solid-state extreme ultraviolet sources, petahertz electronics and optically induced metamaterials.

2 000 000 €

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

Charge and energy transfer are the key steps underlying most chemical reactions and biological transformations. The purely electronic dynamics that control such processes take place on attosecond time scales. A complete understanding of these dynamics on the electronic level therefore calls for new experimental methods with attosecond resolution that are applicable to aqueous environments. We propose to combine the element sensitivity of X-ray spectroscopy with attosecond temporal resolution and ultrathin liquid microjets to study electronic dynamics of relevance to chemical, biological and photovoltaic processes. We will build on our recent achievements in demonstrating femtosecond time-resolved measurements in the water, attosecond pho-toelectron spectroscopy on a liquid microjet and measuring and controlling attosecond charge migration in isolated molecules. We will first concentrate on liquid water to study its electronic dynamics following outer-valence ionization, the formation pathway of the solvated electron and the time scales and intermolecular Coulombic decay following inner-valence or core-level ionization. Second, we will turn to solvated species and measure electronic dynamics and charge migration in solvated molecules, transition-metal complexes and pho-toexcited nanoparticles. These goals will be achieved by developing several innovative experimental tech-niques. We will develop a source of isolated attosecond pulses covering the water window (285-538 eV) and combine it with a flat liquid microjet to realize attosecond transient absorption in liquids. We will complement these measurements with attosecond X-ray emission spectroscopy, Auger spectroscopy and a novel hetero-dyne-detected variant of resonant inelastic Raman scattering, exploiting the large bandwidth that is naturally available from attosecond X-ray sources.

2 750 000 €

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

The aggregation of proteins into amyloid fibrils is involved in various diseases which place a high burden on patients, families, caregivers, and healthcare systems, including Alzheimer’s disease, Parkinson’s disease and type 2 diabetes. While the therapeutic potential of the inhibition of amyloid formation and spreading has been recognized, there is a lack of effective strategies targeting the early steps of the aggregation reaction. In BETACONTROL, I want to establish a structure-guided approach to the control of amyloid formation and spreading. I will develop small molecule and polypeptide-based ligands that interfere with the initial phases of amyloid formation and thereby suppress any toxic oligomeric or fibrillar assemblies. The ligands will target beta-hairpin molecular recognition features, which I found to be readily accessible in disease-related amyloidogenic proteins. Targeting beta-hairpins enables retardation of protein aggregation by substoichiometric amounts of the ligand, affording inhibition of amyloid formation at low compound concentrations. As the strategy addresses the common propensity of amyloidogenic proteins to adopt beta-structure, it will be applicable to a wide range of proteins associated with various diseases. BETACONTROL will yield molecular-level insight into the mechanistic basis of amyloid formation and spreading. Furthermore, it will elucidate the significance of beta-hairpins as molecular recognition features in intrinsically disordered proteins (IDPs) and highlight the applicability of these features as targets for interference with protein-protein interactions of IDPs. Ultimately, BETACONTROL will provide a novel therapeutic approach to a range of devastating diseases.

1 920 697 €

Start date: 2017-06-01, End date: 2022-05-31