Goldman, Nathan

Date: Monday, February 2, 2015
Time: 10:30
Place: ETH Zurich, Hönggerberg, HPF G 6
Host: Rémi Desbuquois / Tilman Esslinger

Creating and Probing Topological Matter in a Cold Atomic Gas

Nathan Goldman
Université Libre de Bruxelles, Belgium

Quantum systems can reach unusual states of matter when they are driven by fast time-periodic modulations.

In this context, optical lattices are ideally suited for generating a wide family of time-dependent potentials, which can be used to prepare interesting band structures for cold atoms. In this talk, I will show how topological Bloch bands can be prepared using modulated optical superlattices. I will present an effective-Hamiltonian framework, which thoughtfully describes the dynamics of the periodically-driven atomic gas. I will then discuss methods to probe the topological features of the underlying band structure, such as the topologically invariant Chern number. Finally, I will report on recent experimental measurements, which revealed the Chern number in an optical-lattice setup. These results constitute an important step towards the realization of novel topological states of matter, such as fractional Chern insulators.