Spectral properties of disordered insulating lattice under nonlinear electric field
Kunal Mozumdar, Herbert F. Fotso, Jong E. Han
Published: 2025/3/12
Abstract
Quenched disorder in a solid state system can result in Anderson localization, where electrons are exponentially localized and the system behaves like an insulator. By solving exactly a disordered electronic lattice model out of equilibrium, we investigate the effect of a DC electric field on Anderson localization in an open system, and provide a minimal platform to study disorder-nonequilibrium interplay in electronic lattice systems. We perform steady-state Keldysh Green's function calculations on an infinite lattice with a finite-range of disorder-active region that are coupled to fermion reservoirs. Our solutions out of a fully electronic model verify Mott's temperature scaling of the variable-range-hopping transport and the Lifshitz tail, well-corroborated by the coherent-potential approximation. We further reveal that a nonequilibrium electronic lattice creates a statistical evolution that shows a counterintuitive shift of the distribution edge in the opposite direction of the band edge. The rich evolution of non-thermal statistics highlights the importance of an explicit band structure and the impurity correlations in strong nonequilibrium theories.