Measuring Pair Correlations in Bose and Fermi Gases via Atom-Resolved Microscopy
Ruixiao Yao, Sungjae Chi, Mingxuan Wang, Richard J. Fletcher, and Martin Zwierlein
Phys. Rev. Lett. 134, 183402 (2025)
We demonstrate atom-resolved detection of itinerant bosonic 23Na and fermionic 6Li quantum gases, enabling the direct in situ measurement of interparticle correlations. In contrast to prior work on lattice-trapped gases, here we realize microscopy of quantum gases in the continuum. We reveal Bose-Einstein condensation with single-atom resolution, measure the enhancement of two-particle g(2) correlations of thermal bosons, and observe the suppression of g(2) for fermions; the Fermi or exchange hole. For strongly interacting Fermi gases confined to two dimensions, we directly observe non-local fermion pairs in the BEC-BCS crossover. We obtain the pair size and the short-range contact directly from the pair correlations. In situ thermometry is enabled via the fluctuation-dissipation theorem. Our technique opens the door to the atom-resolved study of strongly correlated quantum gases of bosons, fermions, and their mixtures.