Dephasing due to nuclear spins in large-amplitude electric dipole spin resonance

TL;DR

This paper investigates how nuclear spin-induced dephasing affects electric dipole spin resonance at large drive amplitudes, revealing Gaussian decay behavior and conditions for high-fidelity spin control.

Contribution

It introduces a theoretical framework for understanding nuclear spin effects in large-amplitude EDSR, extending beyond the small-drive regime and aligning with recent experimental observations.

Findings

Transverse nuclear fluctuations cause Gaussian decay of Rabi oscillations.

High spin-flip gate fidelity is achievable at large drive amplitudes.

The theory accurately reproduces decay patterns observed in experiments.

Abstract

We have analyzed effects of the hyperfine interaction on electric dipole spin resonance when the amplitude of the quantum-dot motion becomes comparable or larger than the quantum dot's size. Away from the well known small-drive regime, the important role played by transverse nuclear fluctuations leads to a gaussian decay with characteristic dependence on drive strength and detuning. A characterization of spin-flip gate fidelity, in the presence of such additional drive-dependent dephasing, shows that vanishingly small errors can still be achieved at sufficiently large amplitudes. Based on our theory, we analyze recent electric-dipole spin resonance experiments relying on spin-orbit interactions or the slanting field of a micromagnet. We find that such experiments are already in a regime with significant effects of transverse nuclear fluctuations and the form of decay of the Rabi oscillations can be reproduced well by our theory.