Rashba-splitting of the Dirac points and the symmetry breaking in the strained artificial graphene

TL;DR

This paper theoretically investigates how Rashba spin-orbit interaction and anisotropic strain influence the electronic properties of artificial graphene, revealing Dirac point splitting and symmetry breaking that can be used to control device performance.

Contribution

It introduces a theoretical analysis of Rashba spin-orbit effects and strain-induced symmetry breaking in artificial graphene-like superlattices, highlighting their impact on electronic properties.

Findings

Rashba spin-orbit interaction causes Dirac point splitting.

Anisotropic strain breaks hexagonal symmetry of dispersion surfaces.

Both effects significantly alter measurable electronic characteristics.

Abstract

The effect of Rashba spin-orbit interaction and anisotropic strain on the electronic, optical and thermodynamic properties of artificial graphene-like superlattice composed of InAs-GaAs quantum dots has been considered theoretically. The electronic energy dispersions have been obtained using Green's function formalism in combination with Fourier transformation to the reciprocal space and an exact diagonalization technique. We have observed a splitting of Dirac points and appearance of edditional Dirac-like points due to the Rashba spin-orbit interaction. Breaking of the hexagonal symmetry of the dispersion surfaces caused by the strain anisotropy is observed as well. It is shown that both the spin-orbit interaction and strain anisotropy have a qualitative impact on the measurable characteristics of the considered structure and can be used as effective tools to control the performance of devices based on artificial graphene.