Dissipatively driven hardcore bosons steered by a gauge field

Abstract

The interplay between dissipation, interactions and gauge fields opens the possibility to rich emerging physics. Here we focus on a set-up in which the system is coupled at its extremities to two different baths which impose a current. We then study the system's response to a gauge field depending on the filling. We show that while the current induced by the baths has a marked dependence on the magnetic field at low fillings which is significantly reduced close to half-filling. We explain the interplay between interactions, gauge field and dissipation by studying the system's energy spectrum at the different fillings. This interplay also results in the emergence of negative differential conductivity. For this study we have developed a number-conserving treatment which allows a numerical exact treatment of fairly large system sizes, and which can be extended to a large class of systems.A deeper understanding of the far-from equilibrium transport properties of complex quantum systems would lead to fascinating progress for future nanotechnologies. A particularly interesting challenge is that of characterizing and controlling the transport properties of quantum systems. In such systems manybody effects can induce, remove or shift phase transitions lines. This significantly affects the properties of a system and our ability to control it. Another salient tool used to control transport and induce new phases of matter is a gauge field. The quantum Hall effect is a paramount example of the role of gauge fields on transport properties [1,2]. In a type-II superconductor the increase of the magnitude of the magnetic field can drive a transition from a diamagnetic Meissner phase to a superconductor with an Abrikosov vortex lattice [3]. Adding interactions to this system can lead to even more exotic phases of matter with topological order [4][5][6].The minimal set-up in which such rich phenomenology can be explored is that of coupled chains (a ladder) with a gauge field as the one depicted in Fig.1. This system has attracted intense theoretical scrutiny [7-23] and it has been experimentally studied both with Josephsonjunctions arrays [24][25][26][27] and with ultracold gases with bosons and fermions [28][29][30], thanks to the use of synthetic gauge fields [31,32].Here we will consider a quantum system in presence of a gauge field and connected at its extremities to two different baths which would impose a current through it (so called boundary dissipatively driven systems). Ion trap experiments promise to be an ideal set-up for a clean realization and study of such transport problems [33][34][35]. The set-up could be realized using ion micro-cavity arrays with a nonlinear local potential [35][36][37][38][39], for which the gauge field is generated by Raman coupling [40]. It should be noted that magnetic fields have already been used to effectively modify heat transport in Josephson junctions [41].Recently, a boundary driven coupled chains of free bosons under the effect of a gauge field was studied [42]. There it was shown t...

Giant Spin Current Rectification Due to the Interplay of Negative Differential Conductance and a Non-Uniform Magnetic Field

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Period doubling in period-one steady states

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