Research

Overview

Our group studies the collaborative behavior of electrons, primarily through the lens of quantum transport. The electronic conductance is an key property of any condensed matter system and contains vital information about the active degrees of freedom at low temperatures. Thermal and thermoelectric transport measurements can reveal even more intricate details about electronic correlations. Our group develops field-theoretical techniques for studying transport phenomena. We combine them with numerical tools and apply them to various experimentally relevant systems. We are especially interested in systems where the interplay of multiple effects such as superconductivity, disorder, and spin-orbit coupling causes new phases of matter to emerge. We also study charge and spin transfer through chiral organic molecules. Such systems, which are the building blocks of life, demonstrate rich and surprising spin physics that remain poorly understood.

Transport through organic molecules

Electron transfer through organic molecules is an essential part of basic biological processes such as respiration and photosynthesis. Surprisingly, nature has implemented electron transport in organisms via insulating molecules. While organic molecules typically exhibit a very complex structure, their transport properties are usually characterized by striking universal features. These can be understood using concepts of classic solid-state physics problems: the spin and charge transport properties of quasi-one-dimensional wires.

New phenomena in superconductors

Superconductivity is one of the most striking examples where even weak interactions can qualitatively change the properties of an electronic system. It has been known to occur in many metals and alloys for over a century, and the basic mechanisms have been well understood for many decades. Despite the maturity of this field, newly synthesized materials, as well as theoretical development, continue to throw up surprises that defy the established framework.

Electric and thermal transport of correlated electrons

Historically, measurements of electronic transport have often given the first indication of new physical concepts arising from interaction effects in condensed matter systems. Famous examples range from metal-insulator transitions and superconductivity to the Kondo and fractional quantum Hall effects. When measurements of the electric conductivity are supplemented by thermal transport experiments, even more profound insights on the many-body effects may be gained.