Energy spectrum and optical absorption of superlattices under strong band inversion conditions

TL;DR

This paper investigates the electronic and optical properties of superlattices with strong band inversion, revealing the absence of hybridization gaps and the presence of Dirac cone crossings, which affect optical absorption behavior.

Contribution

It demonstrates that strong band inversion in superlattices leads to Dirac cone crossings without hybridization gaps, altering optical absorption characteristics.

Findings

No hybridization gap exists in strongly inverted superlattices.

Optical absorption lacks a threshold and decreases gradually at low energies.

Presence of Dirac cones at band crossing points.

Abstract

We show that in superlattices with a strong band inversion no hybridization gap exists. There are two points where the bands are crossing and the spectrum has a shape of Dirac cones. Due to the absence of the hybridization gap the optical absorption does not have a threshold and goes to zero gradually with the decrease of optical energy.