Supression of magnetic subbands in semiconductor superlattices driven by a laser field

TL;DR

This paper explores how strong laser fields influence magnetic subbands in semiconductor superlattices, revealing conditions that lead to band suppression, electron localization, and dominance of multiphotonic optical processes.

Contribution

It introduces a detailed analysis of magnetic subband suppression under laser irradiation using the Kramers-Henneberger approximation, highlighting new effects at accessible laser intensities.

Findings

Magnetic subbands become flat at specific laser frequencies.

Magnetotunneling is significantly inhibited.

Multiphotonic absorption processes dominate under certain conditions.

Abstract

The effect of strong laser radiation on magnetic subbands in semiconductor superlattices is investigated. Due to the presence of a magnetic field perpendicular to the growth direction, non-linear effects such as band supression and electron localization become relevant at relatively lower intensities and for any polarization perpendicular to the magnetic field. Electron quasienergies and density of states are calculated in the Kramers-Henneberger approximation, whose validity is discussed. The conditions under which collapse of magnetic subbands and quenching of N-photon emission or absorption processes occur are discussed. We conclude that at laser frequencies close to cyclotronic frequency and intensities typical of c.w. lasers, magnetic subbands become flat, magnetotunneling is inhibited and multiphotonic processes dominate optical absorption.