"Quantum Gas Microscopy of Fermions in the Continuum"
Quantum gas microscopy has emerged in the last decade as a powerful technique to probe and manipulate quantum many-body systems at the single-atom level. So far, however, it has only been used to study lattice and spin chain physics, prominently to explore the Hubbard model and its generalizations. In this talk, I will present our recent efforts to extend quantum gas microscopy to the study of fermionic many-body systems in continuous space and characterize them at previously inaccessible levels of resolution and control. Firstly, I will show its use to image the in-situ density probability of deterministically prepared single-atom wave packets as they expand in a plane, and how we obtain a crucial benchmark for the reliability of our imaging protocol [1]. Secondly, I will report on quantum gas microscopy of 2D and quasi-2D ideal Fermi gases, where we measure spatially-resolved density correlation functions of the second and third order, and reveal their temperature dependence. Finally, using the same samples, we extract the number fluctuations in the system and perform accurate fluctuation-thermometry over a large dynamical range, from nearly zero temperature to several times the Fermi temperature. By probing number fluctuations on small subsystems, we are able to find a regime where quantum fluctuations play an important role, leading to a significant deviation from the behavior predicted for fermions by the fluctuation-dissipation theorem in the thermodynamic limit. These results represent the first application of quantum gas microscopy to continuous-space many-body systems. Our approach offers radically new possibilities for the exploration of strongly interacting Fermi gases at the single-atom level.
[1] J. Verstraten, K. Dai, M. Dixmerias, B. Peaudecerf, T. de Jongh, and T. Yefsah, arXiv:2404.05699 (2024)
Research Overview: https://www.lkb.upmc.fr/ultracoldfermigases/yefsah/
