Research

Correlated materials show some of the most intriguing phenomena in physics such as exotic magnetism, non-Fermi liquid behavior, or superconductivity with high-transition temperatures. These fascinating and practically useful effects all stem from the fact that the electrons strongly interact with each other via the Coulomb interaction: the state of one electron crucially depends on the state of all the others. Strong correlations are present in a whole range of materials from transition metal oxides and intermetallic compounds such as heavy fermions, cuprate superconductors and iron pnictides and chalcogenides to oxide heterostructures such as LaAlO3/SrTiO3. In these materials, the competition of interactions between charge, spin, orbital and lattice degrees of freedom results in rich equilibrium phase diagrams, and the exploration away from equilibrium has just started.

My group investigates non-equilibrium dynamics of strongly correlated quantum materials and the effects of competing interactions and emergent order on the electronic properties of solids. Our research is often guided by experimental results and strives to understand the impact of strong interactions on the properties of quantum materials with the ultimate goal of contributing to the development of new functional materials.

Non-equilibrium dynamics in correlated quantum materials

Investigations of non-equilibrium dynamics and the excited states have recently shifted into the research focus due to experimental progress in ultrafast laser techniques that allow to probe systems on femtosecond timescales. On the theoretical side, there remain fundamental open questions regarding the description of non-equilibrium dynamics in many-body systems and the interpretation of pump-probe experiments. Read more about Non-equilibrium dynamics in correlated quantum materials

Competing interactions in electronic systems

Strong correlations among electrons, which are caused by the Coulomb repulsion among them, induce a rich behavior of materials. Prominent examples are frustrated magnetic or unconventional superconducting states. Another example are materials which cannot be described by Fermi-liquid theory, for example, due to the strong interaction of conduction electrons with localized moments as occurs in heavy fermions systems. A more recent focus of research has been on materials such as iridium oxides where a unique combination of strong spin-orbit coupling, crystal field splitting and electron-electron correlations lead to exotic phases arising from the interplay of topology and Coulomb interactions.  Read more about Competing interactions in electronic systems

Mesoscopic physics

Our group has an interest in studying optical and transport properties of mesoscopic systems such as graphene, semiconductor and oxide heterostructures. Specific research projects are percolation in field-effect gated complex oxide films, interaction effects on the optical conductivity in graphene and light emission properties of a superconducting LED. Read more about Mesoscopic physics

Condensed Matter Journal Club

We are meeting Wednesday, 5:00 PM in Room 18. Our journal club is an informal meeting of graduate students, postdocs and professors to discuss recent trends and how our own research is related to that. To maintain some coherence, we plan to discuss each topics in a series of meetings often using different publications. Read more about Condensed Matter Journal Club