Towards a quantum gas microscope with reduced hole heating for low temperature Fermi-Hubbard physics*

In recent years, ultracold atoms trapped in optical lattices have emerged as a promising platform to study the Fermi-Hubbard model (FHM), which is notoriously challenging to solve with analytical or numerical techniques. However, despite tremendous progress, there is still a significant discrepancy in temperature between state-of-the-art quantum simulation experiments and the estimated temperature to explore intriguing phases predicted to emerge at low temperatures in the FHM. 

One key hypothesis is that heating due to holes stochastically generated deep in the Fermi sea is the primary mechanism preventing experiments from reaching lower temperatures. We posit that background gas collisions due to imperfect vacuum; off-resonant scattering and laser intensity noise; and three-body loss mechanisms are primary hole-generation mechanisms that limit current experimentally-achievable temperatures for bulk cold atomic Fermi gases. Suppressing the hole generation rates from these mechanisms could provide a path to achieve much lower temperatures in cold-atom Fermi-Hubbard systems.

Here we present a quantum gas microscope designed to target these hole generation mechanisms, with specific focus on achieving single-particle vacuum lifetimes above 1,000 seconds in a room-temperature system. We report a high flux 2D MOT Li atomic source and progress towards quantitative studies of evaporative cooling and measurements of hole generation rates in a 3D Fermi gas.