Who: Thierry Giamarchi, Ecole de Physique, University of Geneva
Date: Wednesday, 22 June 2022, 15:00
I will discuss in this talk the Hall resistance of quantum systems. Hall resistance is supposed , in the "classical" derivation, to give access to the number of carriers in a system. For non-interacting materials we know since the works of Thouless that the Hall resistance is related to topological invariants. However such an understanding does not exist when interactions are present, which makes the computation of Hall resistance quite challenging. I will discuss this question both for the case of coupled one dimensional quantum chains and for the case of a ladder. The former situation is directly relevant to the case of organic conductors and superconductors, and I will discuss the results in connection with experimental measurements in these systems. The latter has been recently realized in cold atomic gases. Such systems provide an unprecedented level of control on the interactions and thus a detailed comparison with the theoretical predictions. I will show that a universal regime exists for the Hall resistance even in the presence of interactions, and discuss these results in comparison with the experimental ones.
Host: Miguel A. Cazalilla