Measuring correlations from the collective spin fluctuations of a large ensemble of lattice-trapped dipolar spin-3 atoms

TL;DR

This study measures collective spin fluctuations in a large ensemble of lattice-trapped dipolar spin-3 atoms to observe the development of two-body correlations driven by long-range dipolar interactions.

Contribution

It introduces a method to characterize quantum correlations in large spin systems through fluctuation measurements, extending analysis beyond spin-1/2 particles.

Findings

Observed dynamical growth of pairwise correlations

Validated quantum nature of correlations via simulations

Demonstrated fluctuation measurements as a tool for many-body systems

Abstract

We perform collective spin measurements to study the buildup of two-body correlations between $\approx10^4$ spin $s=3$ chromium atoms pinned in a 3D optical lattice. The spins interact via long range and anisotropic dipolar interactions. From the fluctuations of total magnetization, measured at the standard quantum limit, we estimate the dynamical growth of the connected pairwise correlations associated with magnetization. The quantum nature of the correlations is assessed by comparisons with short and long time expansions, and numerical simulations. Our work shows that measuring fluctuations of spin populations provides new ways to characterize correlations in quantum many-body systems, for $s>1/2$ spins