Gate induced g-factor control and dimensional transition for donors in multi-valley semiconductors

TL;DR

This paper investigates how electric and magnetic fields influence donor g-factors in multi-valley semiconductors like silicon and germanium, revealing gate-induced transitions and their effects on spin properties relevant for quantum computing.

Contribution

It introduces a multimillion-atom tight-binding model to compute spin-orbit Stark parameters, providing new insights into g-factor control and dimensional transitions in donor states.

Findings

Good agreement with experimental data for silicon donors.

Gate-induced 3D to 2D wave function transition causes observable g-factor shifts.

Electric and magnetic field orientation significantly affects g-factor Stark shifts.

Abstract

The dependence of the g-factors of semiconductor donors on applied electric and magnetic fields is of immense importance in spin based quantum computation and in semiconductor spintronics. The donor g-factor Stark shift is sensitive to the orientation of the electric and magnetic fields and strongly influenced by the band-structure and spin-orbit interactions of the host. Using a multimillion atom tight-binding framework the spin-orbit Stark parameters are computed for donors in multi-valley semiconductors, silicon and germanium. Comparison with limited experimental data shows good agreement for a donor in silicon. Results for gate induced transition from 3D to 2D wave function confinement show that the corresponding g-factor shift in Si is experimentally observable.