Zener transitions between dissipative Bloch bands. II: Current Response at Finite Temperature

TL;DR

This paper investigates how finite temperature and dephasing affect the electric current response, revealing multiple Zener resonance peaks and their dependence on bandwidth and damping in a two-band model.

Contribution

It extends previous zero-temperature models to include finite temperature effects, analyzing the resulting current response and resonance phenomena in a simple two-band system.

Findings

Current peaks occur near Zener resonances at inverse electric field values.

Peaks become more prominent and numerous with increased bandwidth.

Damping broadens the resonance peaks.

Abstract

We extend, to include the effects of finite temperature, our earlier study of the interband dynamics of electrons with Markoffian dephasing under the influence of uniform static electric fields. We use a simple two-band tight-binding model and study the electric current response as a function of field strength and the model parameters. In addition to the Esaki-Tsu peak, near where the Bloch frequency equals the damping rate, we find current peaks near the Zener resonances, at equally spaced values of the inverse electric field. These become more prominenent and numerous with increasing bandwidth (in units of the temperature, with other parameters fixed). As expected, they broaden with increasing damping (dephasing).