Exchange-controlled single-electron-spin rotations in quantum dots

TL;DR

This paper proposes a theoretical method for fast, high-fidelity single-electron spin rotations in quantum dots using exchange control alone, avoiding spin-orbit coupling and ac fields.

Contribution

It introduces a novel exchange-only control scheme enabling rapid and precise spin rotations in quantum dots, with potential for low error rates.

Findings

Arbitrary spin rotations achievable in ~1 ns

Estimated gate error rate around 10^{-3} in GaAs quantum dots

No need for spin-orbit coupling or ac fields

Abstract

We show theoretically that arbitrary coherent rotations can be performed quickly (with a gating time ~1 ns) and with high fidelity on the spin of a single confined electron using control of exchange only, without the need for spin-orbit coupling or ac fields. We expect that implementations of this scheme would achieve gate error rates on the order of \eta ~ 10^{-3} in GaAs quantum dots, within reach of several known error-correction protocols