Control of a single-particle localization in open quantum systems

¹ Institute of Supercomputing Technologies, Lobachevsky State University of Nizhny Novgorod Nizhny Novgorod, Russia
² Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University of Nizhny Novgorod Nizhny Novgorod, Russia
³ Department of Theoretical Physics, University of Augsburg - Augsburg, Germany

Received: 16 August 2017
Accepted: 17 October 2017

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 dominating 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.