Stark Tuning of Donor Electron Spins in Silicon

TL;DR

This paper demonstrates how electric fields can tune donor electron spins in silicon via Stark shifts, affecting hyperfine coupling and g-factor, with implications for quantum computing.

Contribution

It provides the first detailed measurement of Stark effects on 121Sb donor spins in silicon using pulsed ESR, revealing two distinct Stark effects and strain influence.

Findings

Hyperfine coupling decreases with electric field

Electron g-factor decreases with electric field

Strain induces a linear Stark effect

Abstract

We report Stark shift measurements for 121Sb donor electron spins in silicon using pulsed electron spin resonance. Interdigitated metal gates on top of a Sb-implanted 28Si epi-layer are used to apply electric fields. Two Stark effects are resolved: a decrease of the hyperfine coupling between electron and nuclear spins of the donor and a decrease in electron Zeeman g-factor. The hyperfine term prevails at X-band magnetic fields of 0.35T, while the g-factor term is expected to dominate at higher magnetic fields. A significant linear Stark effect is also resolved presumably arising from strain.