Bloch oscillations, Zener tunneling and Wannier-Stark ladders in the time-domain

TL;DR

This paper analyzes carrier dynamics in semiconductor superlattices under static and periodic electric fields, revealing new features such as strong interband transitions, stable density-matrix plateaus, and quasienergy spectrum responses.

Contribution

It provides a novel time-domain analysis of miniband carrier dynamics, highlighting new phenomena in superlattice behavior under various electric field conditions.

Findings

Strong interband transitions at certain static fields

Stable density-matrix plateaus in low field regime

Dynamic response characterized by quasienergy spectra

Abstract

We present a time-domain analysis of carrier dynamics in a semiconductor superlattice with two minibands. Integration of the density-matrix equations of motion reveals a number of new features: (i) for certain values of the applied static electric field strong interband transitions occur; (ii) in static fields the complex time-dependence of the density-matrix displays a sequence of stable plateaus in the low field regime, and (iii) for applied fields with a periodic time-dependence the dynamic response can be understood in terms of the quasienergy spectra.