Electric-field control of a hydrogenic donor's spin in a semiconductor

TL;DR

This paper demonstrates how AC electric fields can control the spin of a hydrogenic donor in a semiconductor by modulating its wave function, revealing nonlinear g tensor behavior and subharmonic Rabi oscillations.

Contribution

It introduces a numerical approach to analyze spin dynamics of donors under electric fields, highlighting nonlinear effects and novel oscillation phenomena.

Findings

g tensor depends nonlinearly on electric fields

Rapid Rabi oscillations occur at subharmonics of Larmor frequency

Electric-field modulation influences spin dynamics significantly

Abstract

An AC electric field applied to a donor-bound electron in a semiconductor modulates the orbital character of its wave function, which affects the electron's spin dynamics via the spin-orbit interaction. Numerical calculations of the spin dynamics of a hydrogenic donor (Si) embedded in GaAs, using a real-space multi-band k.p formalism, show the high symmetry of the hydrogenic donor state results in strongly nonlinear dependences of the electronic g tensor on applied fields. A nontrivial consequence is that the most rapid Rabi oscillations occur for electric fields modulated at a subharmonic of the Larmor frequency.