Feb 01, 2018 4:00 pm - Nielsen Hall 170 - Colloquium
Bryce Gadway - University of Illinois
Observation of the topological Anderson insulator in disordered atomic wires

Disorder and topology have many deep connections, and can have a rich combined influence on the transport properties of quantum particles. Some of the most useful and intriguing properties of topological systems, like the integer quantum Hall gases of two-dimensional electrons, relate to the robustness of their edge states with respect to weak disorder. Rich physics is expected to occur as strong disorder is added to such systems, resulting in the global unwinding of the non-local, topological order. Surprisingly, it has even been predicted, nearly a decade ago, that disorder can induce topological properties in normal materials. Despite these deep and rich connections, the difficulty of creating controlled disorder in real materials has prevented the exploration of disorder-driven changes in topology in any experimental system. Here we describe how an experiment based on extremely dilute atomic gases at ultracold temperatures can mimic the physics of disordered topological materials. We describe the observation of disorder-induced topology in one-dimensional atomic wires, relating to the topological Anderson insulator phase predicted nearly a decade ago. We also describe experiments on the interplay of disorder and large effective magnetic fields for cold atoms, as well as future prospects for the realization of interacting topological matter based on strong atomic interactions.