Coherent electron dynamics in a two-dimensional random system with mobility edges

TL;DR

This study numerically investigates the dynamics of a one-electron wave packet in a 2D random lattice with correlated disorder under an electric field, revealing Bloch-like oscillations linked to delocalized states and their bandwidth.

Contribution

It demonstrates the emergence of Bloch-like oscillations in a 2D disordered system with long-range correlations, connecting oscillation amplitude to the phase's bandwidth.

Findings

Wave packet exhibits Bloch-like oscillations in strong correlation regime.

Oscillation amplitude measures the phase's bandwidth.

Two main frequencies are identified, related to potential structure.

Abstract

We study numerically the dynamics of a one-electron wave packet in a two-dimensional random lattice with long-range correlated diagonal disorder in the presence of a uniform electric field. The time-dependent Schr\"{o}dinger equation is used for this purpose. We find that the wave packet displays Bloch-like oscillations associated with the appearance of a phase of delocalized states in the strong correlation regime. The amplitude of oscillations directly reflects the bandwidth of the phase and allows to measure it. The oscillations reveal two main frequencies whose values are determined by the structure of the underlying potential in the vicinity of the wave packet maximum.