title: Probing nearest-neighbor correlations of ultracold fermions in an optical lattice.
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.
authors.affiliation: Institute for Quantum Electronics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Greif
authors.forename: Leticia
authors.initials: L
authors.lastname: Tarruell
authors.forename: Thomas
authors.initials: T
authors.lastname: Uehlinger
authors.forename: Robert
authors.initials: R
authors.lastname: Jördens
authors.forename: Tilman
authors.initials: T
authors.lastname: Esslinger