Effect of dephasing on the current through a periodically driven quantum point contact

Abstract

We consider two one-dimensional quantum $XX$ magnets linked by a periodically driven quantum point contact (QPC). If magnets are initially polarized in opposite directions, one expects that a spin current through the QPC will establish. It has been shown recently [Phys. Rev. B 103, L041405 (2021)] that, in fact, when the driving frequency exceeds a critical value, the current halts completely, the QPC being effectively insulating. Here we enquire how this picture is affected by quantum dephasing. Our findings reveal that any non-zero dephasing restores the current.