Antiferromagnetic noise correlations in optical lattices

TL;DR

This paper demonstrates how noise correlations in time-of-flight experiments can reveal antiferromagnetic order in fermionic atoms within optical lattices, providing a method to detect and analyze magnetic phase transitions.

Contribution

It introduces a combined analytical and quantum Monte Carlo approach to detect AF correlations via noise measurements in realistic experimental setups.

Findings

AF correlations detectable above and below critical temperature

Spin-resolved noise correlations reveal spin ordering

Method to extract spin correlation length and critical exponent

Abstract

We analyze how noise correlations probed by time-of-flight (TOF) experiments reveal antiferromagnetic (AF) correlations of fermionic atoms in two-dimensional (2D) and three-dimensional (3D) optical lattices. Combining analytical and quantum Monte Carlo (QMC) calculations using experimentally realistic parameters, we show that AF correlations can be detected for temperatures above and below the critical temperature for AF ordering. It is demonstrated that spin-resolved noise correlations yield important information about the spin ordering. Finally, we show how to extract the spin correlation length and the related critical exponent of the AF transition from the noise.