Solution of electric-field-driven tight-binding lattice in contact with fermion reservoir

TL;DR

This paper analytically solves a driven tight-binding lattice model coupled to fermionic reservoirs, revealing an oscillatory steady state with unique electronic properties and classical-like conductivity despite quantum effects.

Contribution

It provides an exact solution to a time-dependent quantum lattice model with dissipation, showing how steady states and conductivity emerge under electric fields.

Findings

Steady state exhibits oscillations due to electric field and dissipation.

Fermi surface disappears regardless of damping or field strength.

Conductivity matches classical Ohmic behavior despite quantum dynamics.

Abstract

Electrons in tight-binding lattice driven by DC electric field dissipate their energy through on-site fermionic thermostats. Due to the translational invariance in the transport direction, the problem can be block-diagonalized. We solve this time-dependent quadratic problem and demonstrate that the problem has an oscillatory steady-state. The steady-state occupation number shows that the Fermi surface disappears for any damping from the thermostats and any finite electric field. Despite the lack of momentum scattering, the conductivity takes the same form as the semi-classical Ohmic expression from the relaxation-time approximation.