Bosonic mixtures in two dimensions (Volker Karle)

In this talk a two-component bosonic gas in two dimensions at low temperatures with zero-range repulsive interaction is considered. In our work we focus on the coexistence phase with superfluid behavior in both components, where a new phenomenon appears: The non-dissipative drag, also called Andreev-Bashkin effect, as a result of the interbosonic interactions, which leads to a modification of the usual BKT-transition. Quantum fluctuations of the elementary excitations lead to further corrections of the phase boundary. We study the renormalization of the densities at finite temperatures using standard RG-methods.