Cross-section geometry effects in the subband structure and spin-related properties of a HgTe/CdTe nanowire

TL;DR

This paper theoretically investigates how the geometry of a HgTe/CdTe nanowire, especially a longitudinal groove, affects its electronic subband structure and spin properties, enabling control of spin-polarized currents via electric fields.

Contribution

It introduces a detailed theoretical model showing how geometrical features and external electric fields influence spin-related properties in HgTe/CdTe nanowires, revealing new ways to manipulate spin currents.

Findings

Geometry significantly affects subband dispersion and spin properties.

External electric fields enable modulation of spin-polarized currents.

Rich subband structure allows for spin control without magnetic fields.

Abstract

By means of a multiband effective mass Hamiltonian, a theoretical characterization of the effect of the geometrical features of the confinement profile --in particular, a longitudinal groove-- on the subbands dispersion and spin-related properties of a rectangular HgTe/CdTe nanowire is presented. Through an external electric field applied perpendicular to the wire, the interplay of the induced Rashba spin splitting and these geometrical features is investigated. It is found that by exploiting this interplay a rich complexity of the subband structure arises, permitting the generation and modulation of spin-polarized currents without magnetic fields.