Tue November 10, 2015 4:00 pm
Quantum Quenches in Chern Insulators
Location:MIT 26-214
Dr. Nigel Cooper,
Cavendish Laboratory - University of Cambridge
Ten Minute Talk:"Interferometric measurement scheme for topological invariants of correlated many-body systems" by
Fabian Grusdt
The development of optical lattices that imprint artificial gauge fields now allows the creation of energy bands for cold atoms with non-trivial topological character, as encoded in a non-zero Chern number. At equilibrium, the Chern number is known to control key qualitative features of the system, notably the number of gapless edge states. I shall describe theoretical predictions for the properties of the non-equilibrium states induced by changing the band topology of cold atom systems in real time. I shall focus on a band filled with non-interacting fermions, and describe the dynamics induced by quantum quenches between topological and non-topological phases. A notable feature is that the Chern number of the state, calculated for a bulk system, is unchanged under the dynamics following such a quench. However, the edge currents relax towards their new equilibrium values, indicating a necessary distinction between Chern number of the state and the edge structure in these non-equilibrium settings.