Quantum Gas Microscopy of Fermionic Matter in Continuous Space

In the last decade, quantum gas microscopy has emerged 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 for the study of 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 singleatom 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 a quasi-2D ideal Fermi gas, where we measure spatially-resolved density correlation functions of the second and third order, and reveal their temperature dependence. From the same samples, we also extract the number fluctuations in small subsystems of the cloud where zero temperature quantum fluctuations play an important role, leading to a significant deviation from the behavior predicted by the fluctuationdissipation theorem in the thermodynamic limit. Our ability to distinguish the quantum and thermal fluctuation contributions allows us to perform accurate fluctuation-thermometry over a large dynamical range, from nearly zero temperature to several Fermi temperatures. 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)