Magnetic Field-Induced Fano Profiles in the Absorption Coefficient of Semiconductors

TL;DR

This paper reports the discovery of Fano-like asymmetric resonance profiles in the magneto-absorption spectra of bulk semiconductors, attributed to quasi-one-dimensional electronic excitations and scattering effects.

Contribution

It introduces the observation of Fano profiles in magneto-absorption and explains their origin in the quasi-one-dimensional nature of hot electron-hole pairs.

Findings

Fano-like resonance profiles observed in magneto-absorption.

Renormalization of absorption profiles due to electronic excitation character.

Qualitative agreement with experimental data.

Abstract

A strongly asymmetric, Fano-like resonance profile has been found for magneto-absorption in the states of hot free electron-hole pairs scattered by defects in bulk semiconductors. The renormalization of the absorption profile, compared to that expected from the bare density of states in a high magnetic field, follows from a quasi-one-dimensional character of electronic excitations. The results are valid for absorption by the electronic states of large Landau quantum number where the Coulomb interaction should play a minor role. The resonance shape is in a good qualitattive agreement with experimental observations.