Dephasing enhanced transport in boundary-driven quasiperiodic chains

We study dephasing enhanced transport in boundary-driven quasiperiodic systems. Specifically, we consider dephasing modeled by current-preserving Lindblad dissipators acting on the noninteracting Aubry-Andre-Harper and Fibonacci bulk systems. The former is known to undergo a critical localization transition with a suppression of ballistic transport above a critical value of the potential. At the critical point, the presence of nonergodic extended states yields anomalous subdiffusion. The Fibonacci model, on the other hand, yields anomalous transport with a continuously varying exponent depending on the potential strength. By computing the covariance matrix in the nonequilibrium steady state, we show that sufficiently strong dephasing always renders the transport diffusive. The interplay between dephasing and quasiperiodicity gives rise to a maximum of the diffusion coefficient for finite dephasing, which suggests that the combination of quasiperiodic geometries and dephasing can be used to control noise enhanced transport.

Automated summary

The study investigates dephasing enhanced transport in boundary-driven quasiperiodic systems. Modeling dephasing with current-preserving Lindblad dissipators on noninteracting Aubry-André-Harper and Fibonacci bulk systems, it is found that sufficiently strong dephasing can render transport diffusive and control noise enhanced transport. The interplay between dephasing and quasiperiodicity leads to a maximum diffusion coefficient for finite dephasing, highlighting the potential of combining quasiperiodic geometries and dephasing for transport control.