Antiferromagnetic noise correlations in optical lattices
Prof. Dr. Georg M. Bruun (Niels Bohr Institut, Universität Kopenhagen)

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.