Single-atom-resolved detection in optical lattices using quantum-gas microscopes has enabled a new generation of experiments in the field of quantum simulation. While such devices have been realized with bosonic species several years ago, a fermionic quantum-gas microscope has proven more challenging and has only become available very recently.
In our experiment, we demonstrated single-site- and single-atom-resolved florescence imaging of fermionic potassium-40 atoms in a quantum-gas microscope setup using electromagnetically-induced-transparency cooling. We detected on average 1000 fluorescence photons from a single atom within 1.5 s, while keeping it close to the vibrational ground state of the optical lattice.
This fermionic quantum-gas microscope will provide the possibility to probe quantities that are difficult to access directly, such as spin-spin-correlation functions or string-order. It would allow the study of out-of-equilibrium dynamics, the spreading of correlations and the build-up of entanglement in many-particle fermionic quantum systems. It could perform quantum simulation of the Fermi-Hubbard model, which is conjectured to capture the key mechanism behind high-temperature superconductors,