Measuring finite-range phase coherence in an optical lattice using   Talbot interferometry
  One of the important goals of present research is to control and manipulate coherence in a broad variety of systems, such as semiconductor spintronics, biological photosynthetic systems, superconducting qubits and complex atomic networks. Over the past decades interferometry of atoms and molecules has proven to be a powerful tool to explore coherence. Here we demonstrate a near-field interferometer based on the Talbot effect, which allows to measure finite-range phase coherence of ultracold atoms in an optical lattice. We apply this interferometer to study the build-up of phase coherence after a quantum quench of a Bose-Einstein condensate residing in a one-dimensional optical lattice. Our technique of measuring finite-range phase coherence is generic, easy to adopt, and can be applied in practically all lattice experiments without further modifications. 
Bodhaditya Santra, Christian Baals, Ralf Labouvie, Aranya B.   Bhattacherjee, Axel Pelster and Herwig Ott
quant-ph cond-mat.quant-gas