Phonon induced spin squeezing based on geometric phase

TL;DR

This paper proposes a method to generate spin squeezing via geometric phase induced by a mechanical mode, with results showing how thermal noise, quality factor, and ensemble size influence squeezing, and how control pulses suppress bath coupling.

Contribution

It introduces a novel scheme for spin squeezing based on geometric phase, including analytical and numerical analysis of its dependence on system parameters and control techniques.

Findings

Spin squeezing depends on thermal excitation, quality factor, and ensemble size.

Bang-Bang control pulses effectively suppress bath coupling.

High quality factor enables ideal spin squeezing in NV ensembles.

Abstract

A scheme to achieve spin squeezing using a geometric phase induced by a single mechanical mode is proposed. The analytical and numerical results show that the ultimate degree of spin squeezing depends on the parameter $\frac{n_{th}+1/2}{Q\sqrt{N}}$, which is the ratio between the thermal excitation, the quality factor and square root of ensemble size. The undesired coupling between the spin ensemble and the bath can be efficiently suppressed by Bang-Bang control pulses. With high quality factor, the ultimate limit of the ideal one-axis twisting spin squeezing can be obtained for an NV ensemble in diamond.