Real-time switching between multiple steady-states in quantum transport

Abstract

We study transport through an interacting model system consisting of a central correlated site coupled to finite bandwidth tight-binding leads, which are considered as effectively noninteracting. Its nonequilibrium properties are determined by real-time propagation of the Kadanoff-Baym equations after applying a bias voltage to the system. The electronic interactions on the central site are incorporated by means of self-energy approximations at Hartree-Fock, second Born and GW level. We investigate the conditions under which multiple steady-state solutions occur within different self-energy approximations, and analyze in detail the nature of these states from an analysis of their spectral functions. At the Hartree-Fock level at least two stable steady-state solutions with different densities and currents can be found. By applying a gate voltage-pulse at a given time we are able to switch between these solutions. With the same parameters we find only one steady-state solution when the self-consistent second Born and GW approximations are considered. We therefore conclude that treatment of many-body interactions beyond mean-field can destroy bistability and lead to qualitatively different results as compared those at mean-field level.

10 pages, 8 figures, Submitted at "Progress in Nonequilibrium Green's Functions IV" conference

References in corpus (4)

• Time-dependent transport in interacting and non-interacting mesoscopic systems
• Time-dependent quantum transport: A practical scheme using density functional theory
• Time-Dependent Partition-Free Approach in Resonant Tunneling Systems
• Conserving approximations in time-dependent quantum transport: Initial correlations and memory effects

Cited by in corpus (5)

• Comparative study of many-body perturbation theory and time-dependent density functional theory in the out-of-equilibrium Anderson model
• Correlation effects in bistability at the nanoscale: steady state and beyond
• Many-body Green's function theory for electron-phonon interactions: the Kadanoff-Baym approach to spectral properties of the Holstein dimer
• A many-body approach to transport in quantum systems: From the transient regime to the stationary state
• Stability analysis of multiple nonequilibrium fixed points in self-consistent electron transport calculations