Squeezing Classical Antiferromagnets into Quantum Spin Liquids via Global Cavity Fluctuations

TL;DR

This paper demonstrates how cavity quantum electrodynamics can transform classical antiferromagnets into quantum spin liquids by leveraging global cavity fluctuations to induce strong correlations and entanglement.

Contribution

It introduces a novel method to generate quantum spin liquids from classical antiferromagnets using cavity-mediated interactions to project into a highly entangled singlet sector.

Findings

Global cavity fluctuations can induce quantum spin liquids.

The system exhibits non-local entanglement and fractionalized excitations.

Emergent gauge fields are observed in the cavity-coupled Rydberg atom arrays.

Abstract

Cavity quantum electrodynamics with atomic ensembles is typically associated with collective spin phenomena, such as superradiance and spin squeezing, in which the atoms evolve collectively as a macroscopic spin ($S\sim N/2$) on the Bloch sphere. Surprisingly, we show that the tendency toward a collective spin description need not imply collective spin phenomena; rather, it can be exploited to generate new forms of strongly correlated quantum matter. The key idea is to use uniform cavity-mediated interactions to energetically project the system into the total-spin singlet sector ($S=0$) - a highly entangled subspace where the physics is governed entirely by cavity fluctuations. Focusing on Rydberg atom arrays coupled to a single-mode cavity, we show that global cavity fluctuations can effectively squeeze classical antiferromagnets into quantum spin liquids, characterized by non-local entanglement, fractionalized excitations, and emergent gauge fields. This work suggests that cavity QED can be a surprising resource for inducing strongly correlated phenomena, which could be explored in the new generation of hybrid tweezer-cavity platforms.