Flux-controlled skin effect and topological transition in a dissipative two-leg ladder model

Abstract

The synthetic gauge field and dissipation are of crucial importance in both fundamental physics and applications. Here, we investigate the interplay of the uniform flux and the on-site gain and loss by considering a dissipative two-leg ladder model. By calculating the spectral winding number and the generalized Brillouin zone, we predict the non-Hermitian skin effect, whose skin modes display the bipolar localization. This skin effect emerges when the flux is not an integer multiple of $\ensuremath{\pi}$. We further demonstrate the breakdown of the chiral currents due to the presence of the skin effect by studying single-particle dynamics. Moreover, we show that the non-Hermiticity can drive a flux-dependent topological transition characterized by a hidden Chern number. Our results provide a scheme to manipulate the non-Hermitian skin effect and topological phase transitions, which may find potential applications in lasing, light manipulating, and signal processing.