Group Seminar: Realization of an atomic quantum Hall system in four dimensions

Sylvain Nascimbene, Laboratoire Kastler Brossel
Group Seminar at MPQ lecture hall and zoom
Tuesday, January 24th , 09:00am (MEZ)

Abstract:

From 2D quantum Hall systems to 3D topological insulators and Weyl semi-metals, various types of topological states of matter have been realized in condensed matter systems. Thanks to the concept of synthetic dimensions, engineered systems could give access to a larger range of topological systems, predicted to occur in dimensions D > 3. In this talk, I will present the experimental realization of a 4D quantum Hall system using ultracold dysprosium atoms. We use the giant electronic spin of this atom to encode two synthetic dimensions, which we couple to two spatial ones using coherent light. This spin-orbit coupling gives rise to an effective magnetic field acting on the 4D atom dynamics. We reveal the topological nature of this system by measuring a quantized non-linear electromagnetic response, and study the nature of 3D hyperedge modes. We also investigate elementary excitations, corresponding to non-planar cyclotron orbits of the center of mass, beyond the circular orbits encountered in lower dimensions