Detuning Enhanced Cavity Spin Squeezing

TL;DR

This paper theoretically analyzes cavity spin squeezing and finds that large detuning of the driving laser enhances squeezing scaling and suppresses photon scattering, improving quantum measurement precision.

Contribution

It demonstrates that detuning the laser improves the scaling of cavity spin squeezing and reduces photon scattering effects, offering a new approach for quantum measurement enhancement.

Findings

Detuning improves squeezing scaling from S^{-2/5} to S^{-2/3}.

Large detuning suppresses photon scattering into free space.

Theoretical analysis of cavity spin squeezing with detuning.

Abstract

The unconditionally squeezing of the collective spin of an atomic ensemble in a laser driven optical cavity (I. D. Leroux, M. H. Schleier-Smith, and V. Vuletic, Phys. Rev. Lett 104, 073602 (2010)) is studied and analyzed theoretically. Surprisingly, we find that the largely detuned driving laser can improve the scaling of cavity squeezing from $S^{-2/5}$ to $S^{-2/3}$, where S is the total atomic spin. Moreover, we also demonstrate that the experimental imperfection of photon scattering into free space can be efficiently suppressed by detuning.