2024/10/14 by Brüggenjürgen, Justus C., Fischer, Mathis S., Weitenberg, Christof · 2 citations
#FOS: Physical sciences #Quantum Gases (cond-mat.quant-gas) #Quantum Physics (quant-ph) #Statistical Mechanics (cond-mat.stat-mech)
paper · doi:10.48550/arxiv.2410.10611
Coherence properties are central to quantum systems and are at the heart of phenomena such as superconductivity. Here we study coherence properties of an ultracold Bose gas in a two-dimensional optical lattice across the thermal phase transition. To infer the phase coherence and phase fluctuation profile, we use direct matter-wave imaging of higher Talbot revivals as well as a new phase microscope based on a site-resolved mapping of phase fluctuations to density fluctuations during matter-wave imaging. We observe the algebraic decay of the phase correlations in the superfluid phase and a linear temperature increase of the exponent. These techniques will also allow studying coherence properties in strongly-correlated quantum systems with full spatial resolution.