Tomasz Szołdra (27.02, 17:45)
Affiliation: Jagiellonian Universtiy, Poland Title: Measuring topological invariants in optical lattices Abstract:Ultracold atoms in optical lattices form a clean quantum simulator platform to examine topological phenomena and test exotic topological materials. In this talk we will propose an experimental scheme to measure Chern number of two-dimensional multiband topological insulators with bosonic atoms. We will show how to extract the topological invariants out of a sequence of time-of-flight images applying a phase retrieval algorithm to Bose-Einstein Condensate matter waves. We will illustrate advantages of using bosonic atoms as well as efficiency and robustness of the method with two prominent examples: the Harper-Hofstadter model with an arbitrary commensurate magnetic field and the Haldane model on a brick-wall lattice.