QUANTUM OPTICS SEMINAR

Title: Simulation of frustrated magnetism and exotic quantum phases in non-cubic optical lattices

Speaker:        Patrick Windpassinger

Institute for Laser Physics, University of Hamburg, Germany

Time:              Thursday, February 23 at 13:15

Room:            1525-323

Abstract:

The distribution of magnetic moments in a triangular arrangement leads to various magnetic phases which depend on the coupling between adjacent lattice sites. In particular, also frustrated phases are present. Since it is in general rather difficult to adjust the magnitude and sign of these couplings, studying these phases and the phase transitions is rather challenging. In the first part of the talk I will present the experimental realization of a simulator for frustrated magnetism using ultracold bosons in a triangular optical lattice. Besides all possible magnetic phases, spontaneous symmetry breaking between the degenerate ground states in the frustrated part of the phase diagram could be demonstrated and the phase transitions be characterized.

The second part will be concerned with complex superfluid phases in a hexagonal optical lattice. In the particular experimental realization of the hexagonal lattice, the graphene like band structure together with the spin-dependence of the lattice lead to an interaction induced, complex hybridization of the lowest two bands and quantum phases with complex order parameter.

Jan Arlt

Coffee and tea will be served at 13:00