Date: 2011-4-22，10:00am

Venue: Conference Hall 322，Science Building

Title: Disordered bosons and the superconductor-insulator transition

Speaker: Professor Thomas Nattermann

Institut für Theoretische Physik

Universität zu Köln

Germany

Abstract:The description of bosons in disordered potentials requires from the outset the consideration of their interaction. I will show that for low density $n$ a boson condensate decays into fragments. Increasing $n$ the number of fragments increases untill at a critical density $n_c$ the transition to the superfluid proceeds. $n_c$ is determine by the equality of the Larkin and the healing length.

Two applications of our theory will be considered: cold atoms in disordered traps and the insulating phase of a disordered superconductors in an external magnetic field.

(see also Phys. Rev. B 80, 104515 (2009), Phys. Rev. Lett. 105, 267001 (2010))