Group Leader Profiles

The research of our group is concerned with quantum technologies and quantum optics. One particular research focus is quantum networks: we implement quantum protocols, build distributed quantum networks and perform secure quantum computations in them. Furthermore, we work on demonstrating quantum effects in systems with few particles and how to exploit those for applications. Our research is experimental and focuses on photonic quantum systems, meaning we generate, manipulate, and detect single photons. Furthermore, our research is interdisciplinary and involves aspects from physics, engineering, and computer science.

Our research seeks to elucidate the links between the structure and properties of technologically-relevant materials. The primary goal of our work is to advance electrochemical energy storage through the design and control of the atomic and electronic structure, and microstructure of materials, including the discovery of novel compounds, and through the optimization of interfaces and composite structures in devices. Our approach encompasses innovative synthesis approaches, electrochemical testing, as well as the in-depth investigation of structural and electronic phenomena taking place in the electrodes, in the electrolyte, and at their interfaces during battery function. For this, we use complementary diagnostic tools, from state-of-the-art spectroscopy, to diffraction/scattering, to electron microscopy. In particular, we develop high resolution solid-state nuclear magnetic resonance (NMR) spectroscopy, operando and in situ NMR and electron paramagnetic resonance (EPR) spectroscopy, magnetometry, and magnetic resonance imaging (MRI). Another pillar of our work is the development of first principles and statistical mechanics computations to facilitate the interpretation of our experimental results.

Solid state physics, correlated electron systems, molecular quantum materials, van der Waals coupled systems, magnetically frustrated systems, altermagnets, quantum spin liquids, topological materials, Dirac and Weyl electrons, physics of low-dimensional solids, superconductivity, materials for quantum computers, superconducting electronics, electrodynamics of solids, infrared and THz optical measurements of solids, microwave spectroscopy, magneto-optics, ellipsometry,

Polarized x-ray based studies on magnetism and modern magnetic materials utilizing X-ray magnetism circular dichroism (XMCD) and related techniques, like X-ray resonant reflectivity (XRMR), and X-ray spectroscopic microscopy. While beeing focused on Keimer Department research topics, related phenomena are interface magnetism, spin-orbit-coupling and spin-orbit-torque, voltage induced magnetocrystalline anisotropy, orbital moments, nano-magnetism, spin conduction and relaxation, and interfacial exchange interaction.

Our interdisciplinary research group explores how to teach crystals tricks of living matter by investigating dynamic features of molecular framework materials such as metal-organic and covalent organic frameworks (MOFs and COFs). By specifically tuning the structural topology of the framework, we create soft porous crystals which exhibit pore contraction and/or expansion as a response to the adsorption of gases and fluids or external triggers such as light irradiation. Such materials can act as responsive cargo-release systems, nanoscopic sensors or feature counterintuitive phenomena such as negative gas adsorption. We furthermore construct frameworks which contain molecular machines such as light-driven molecular motors and switches as responsive and intrinsically dynamic building blocks. We aim towards collective operating molecular machines in the solid state which are able to actively transport molecules in the pore space and facilitate dynamic conversion and storage of energy carriers and other small molecules. Our diverse team uses a wide range of synthetic and experimental tools and collaborates in national and international research projects to push the boundaries of dynamic features in crystalline solids.

Our research explores the rational synthesis of new functional materials by combining the tools of molecular, solid-state and nanochemistry. Research interests include the design of organic, inorganic and hybrid materials for solar energy conversion and storage, ion conductors for electrochemical energy storage, and “smart” photonic crystals for optical sensing. We aim at creating function from both atomic-scale structure and nanoscale morphology, with a strong emphasis on exploring structure-property relationships based on a variety of diffraction and spectroscopic techniques. Recent activities include the development of molecular frameworks for solar batteries, “dark” photocatalysis, photomemristive sensors, and (photo)electrocatalytic CO2 conversion, the development of quantum materials for (photo)electrocatalysis, as well as the design of lithium and sodium thiophosphate and sulfide solid electrolytes for all-solid-state batteries. 

The work focuses on synthesis and detailed characterization of metal-rich compounds, preferentially containing nitrogen as a constituent. First emphasis is the design and development of preparative techniques as basis for synthesis of novel materials. Special attention is granted to structural characterization, electronic and magnetic properties as well as mechanical and chemical behavior. These data are inevitable for any detailed consideration of chemical bonding and potential applications. • Advanced solid state synthesis of functional materials including various high pressure techniques, solvothermal synthesis and crystal growth, high temperature synthesis • Solid state reaction pathways and crystal growth mechanisms • Magnetic and superconducting materials, ionic conductors

Our research deals with the theoretical description of the emergent collective phenomena that arise in interacting quantum many-body systems, resulting from competing interactions, disorder, and topology. More specifically, we are interested in unconventional and topological superconductivity, complex phase diagrams, the impact of impurities in crystals, spin-orbit coupling, magnetism, spin liquids and topological order, moiré superlattice systems, non-Hermitian many-body physics, and more. To address these problems, we use a combination of analytical and numerical techniques of quantum field theory and statistical mechanics. Furthermore, we explore the potential of machine-learning to address problems of many-body physics.

·       Spectroscopy, especially electron paramagnetic resonance spectroscopy at conventional and high frequencies. We apply and develop a wide range of experimental methods.

·       Molecular Quantum Science and Technologies, understanding, engineering and application of molecules in novel quantum architectures.

·       Molecular Nanomagnets, understanding of electronic structure and magnetic properties of molecular systems with bistable magnetization of molecular origin.

·       Catalysis, application of (THz and conventional) EPR methods in catalysis research, pushing toward in situ and operando investigations.