Multiple-pulse coherence enhancement of solid state spin qubits

TL;DR

This paper demonstrates that applying specially designed multiple-pulse sequences can significantly extend the coherence time of solid state spin qubits by suppressing spectral diffusion caused by nuclear spin dynamics.

Contribution

It introduces a method to enhance spin coherence times in solid state qubits using tailored multiple-pulse sequences, improving upon previous single-pulse techniques.

Findings

Coherence times increased by factors of 4-10 in GaAs quantum dots.

Effective suppression of spectral diffusion via composite pulse sequences.

Potential improvements for solid state quantum computing architectures.

Abstract

We describe how the spin coherence time of a localized electron spin in solids, i.e. a solid state spin qubit, can be prolonged by applying designed electron spin resonance pulse sequences. In particular, the spin echo decay due to the spectral diffusion of the electron spin resonance frequency induced by the non-Markovian temporal fluctuations of the nuclear spin flip-flop dynamics can be strongly suppressed using multiple-pulse sequences akin to the Carr-Purcell-Meiboom-Gill pulse sequence in nuclear magnetic resonance. Spin coherence time can be enhanced by factors of 4-10 in GaAs quantum dot and Si:P quantum computer architectures using composite sequences with an even number of pulses.