Imaging and addressing of individual fermionic atoms in an optical lattice
We demonstrate fluorescence microscopy of individual fermionic potassium atoms in a 527-nm-period optical lattice. Using electromagnetically induced transparency cooling on the 770.1-nm D1 transition of K40, we find that atoms remain at individual sites of a 0.2-mK-deep lattice, with a 1/e pinning lifetime of 67(9)s, while scattering ∼103 photons per second. The plane to be imaged is isolated using microwave spectroscopy in a magnetic-field gradient, and can be chosen at any depth within the three-dimensional lattice. With a similar protocol, we also demonstrate patterned selection within a single lattice plane. High-resolution images are acquired using a microscope objective with 0.8 numerical aperture, from which we determine the occupation of lattice sites in the imaging plane with 94(2)% fidelity per atom. Imaging with single-atom sensitivity and addressing with single-site accuracy are key steps towards the search for unconventional superfluidity of fermions in optical lattices, the initialization and characterization of transport and nonequilibrium dynamics, and the observation of magnetic domains.