Speaker
Description
Investigation of non-equilibrium fermionic transport in a periodically-driven tilted lattice is currently a subject of major interest. Transport properties in this setting are influenced by the drive, tilt, and interactions, as well as the non-Markovian nature of the fermionic reservoirs. We address this setup with two complementary tools, with an ultimate aim at addressing the interplay of all four of these factors in transport: We first formulate quantum transport of driven systems within the extended reservoir approach (ERA), which provides a method to capture continuum reservoirs with both a finite bandwidth and a finite bias. As with non--equilibrium steady states in time--independent scenarios, the current displays a Kramers' turnover including the formation of a plateau region that captures the physical, continuum limit response. We demonstrate that a simple stability criteria identifies an appropriate relaxation rate to target this physical plateau. To benchmark this criteria, we study a non-interacting, one-dimensional driven tilted lattice. The approach recovers well--understood physical behavior in the limit of weak system--reservoir coupling. Extended reservoirs enable addressing strong coupling and non--linear response as well, where we analyze how transport responds to the dynamics inside the driven lattice. In second step, we introduce a many-body density-density interaction and study transport in the fully Markovian limit (e.g., infinite bandwidth and bias). At weak many-body interaction (and weak system-reservoir coupling) the rotating wave approximation captures the various resonance that appear due to the periodic drive. As the many-body interaction increases, a new resonance appears that can display a giant enhancement of conductance. The next step is to put these two sets of results together within tensor networks and study fully many-body quantum transport in a periodically driven system in the presence of finite bias, finite bandwidth reservoirs.
