Probing nearest-neighbor correlations of ultracold fermions in an optical lattice

TL;DR

This paper introduces a new method to measure nearest-neighbor correlations in ultracold fermionic gases in optical lattices, enabling detailed study of magnetic ordering with high accuracy.

Contribution

It presents a novel probing technique based on lattice modulation to access spin and density correlations without fitting parameters.

Findings

Measured correlations match ab initio calculations across temperatures

Probe can detect the approach to magnetic order

Method enhances understanding of quantum magnetism in optical lattices

Abstract

We demonstrate a probe for nearest-neighbor correlations of fermionic quantum gases in optical lattices. It gives access to spin and density configurations of adjacent sites and relies on creating additional doubly occupied sites by perturbative lattice modulation. The measured correlations for different lattice temperatures are in good agreement with an ab initio calculation without any fitting parameters. This probe opens new prospects for studying the approach to magnetically ordered phases.