Electron g-factor in nanostructures: continuum media and atomistic approach

TL;DR

This paper compares continuum and atomistic models to study the electron g-factor in nanostructures, revealing size-dependent spin state anti-crossings caused by symmetry breaking, with implications for spintronics.

Contribution

It introduces a mesoscopic model for InAs nanostructures that aligns well with atomistic calculations across various sizes, highlighting size effects on g-factor and spin states.

Findings

Successful comparison between mesoscopic and atomistic models.

Identification of size-dependent electron spin state anti-crossings.

Demonstration that symmetry breaking causes anti-crossings without shape or strain effects.

Abstract

We report studies of $k$-dependent Land\'e $g$-factor, performed by both continuous media approximation k.p method, and atomistic tight-binding sp$^3$d$^5$s$^*$ approach. We propose an effective, mesoscopic model for InAs that we are able to successfully compare with atomistic calculations, for both very small and very large nanostructures, with a number of atoms reaching over 60 million. Finally, for nanostructure dimensions corresponding to near-zero $g$-factor we report electron spin states anti-crossing as a function of system size, despite no shape-anisotropy nor strain effects included, and merely due to breaking of atomistic symmetry of cation/anion planes constituting the system.