Mardi 06 octobre 2015 à 14h00
Salle 234, Ecole de Physique

Topology and universality in periodically driven many-body systems

Mark Rudner, Niels Bohr Academy, Copenhagen

Propelled by recent experimental advances in controlling a variety of quantum systems using microwave and laser driving fields, time-periodic driving has emerged as a new means for potentially realizing and probing topological phenomena in solid state, optical, and atomic systems. In addition to proposals and recent experiments related to so-called "Floquet topological insulators" -- driven system analogues of the conventional topological insulators -- periodic driving opens the way for entirely new types of non-equilibrium topological phases, without precedent in equilibrium. Examples include chiral one dimensional systems whose Floquet bands feature quantized (non-zero) average group velocities and two-dimensional systems which host robust chiral edge states despite all bulk bands having vanishing Chern numbers. In this talk I will begin by introducing the main ideas of the field and outlining the challenges associated with realizing topological phenomena in driven many-body systems. Within the context of the intriguing new situations mentioned above, I will then discuss how the introduction of interactions and/or disorder can actually lead to robust new universal quantized pumping phenomena. Finally, I will mention prospects for experimental realizations.