Control of a single-particle localization in open quantum systems

TL;DR

This paper explores how tunable dissipation can be used to control localization in open quantum systems, enabling targeted localization or delocalization of states through engineered dissipation mechanisms.

Contribution

It introduces a method to control the localization properties of quantum states via matching dissipative operators with the system's eigenstates, including in disordered systems.

Findings

Localized asymptotic states can be achieved in flat band systems.

Control over localization in disordered Anderson systems is possible.

Dissipative control remains effective despite local dephasing.

Abstract

We investigate the possibility to control localization properties of the asymptotic state of an open quantum system with a tunable synthetic dissipation. The control mechanism relies on the matching between properties of dissipative operators, acting on neighboring sites and specified by a single control parameter, and the spatial phase structure of eigenstates of the system Hamiltonian. As a result, the latter coincide (or near coincide) with the dark states of the operators. In a disorder-free Hamiltonian with a flat band, one can either obtain a localized asymptotic state or populate whole flat and/or dispersive bands, depending on the value of the control parameter. In a disordered Anderson system, the asymptotic state can be localized anywhere in the spectrum of the Hamiltonian. The dissipative control is robust with respect to an additional local dephasing.