Universal phase shift and non-exponential decay of driven single-spin oscillations

TL;DR

This paper reveals that driven single-electron spins exhibit a universal phase shift of approximately pi/4 and decay following a power law, due to the long correlation time of the nuclear spin bath, with both theoretical and experimental validation.

Contribution

It provides a theoretical derivation and experimental confirmation of the universal phase shift and non-exponential decay in driven single-spin oscillations.

Findings

Oscillations show a phase shift of about pi/4.

Decay follows a power-law behavior.

Theoretical model matches experimental results.

Abstract

We study, both theoretically and experimentally, driven Rabi oscillations of a single electron spin coupled to a nuclear spin bath. Due to the long correlation time of the bath, two unusual features are observed in the oscillations. The decay follows a power law, and the oscillations are shifted in phase by a universal value of ~pi/4. These properties are well understood from a theoretical expression that we derive here in the static limit for the nuclear bath. This improved understanding of the coupled electron-nuclear system is important for future experiments using the electron spin as a qubit.