Fermi Gas Microscopy Beyond the Square Lattice Geometry

Quantum gas microscopy with fermionic atoms provides new insights into the rich quantum phases in the Fermi-Hubbard model. Beyond the standard square lattice, nonstandard band structures are believed to host novel quantum phases, from unconventional superconductors in honeycomb lattices to chiral spin liquids in kagome lattices. Thus, to expand the capability of our quantum gas microscope for studying a broader range of correlated phases, we implemented an optical lattice whose potential can be tuned to realize triangular, honeycomb, and non-bipartite square geometries. This is achieved by actively phase-locking two lattice beams to create an interfering lattice and using a third beam to adjust the lattice depth along one direction. With our tunable lattice, we were able to investigate the magnetic order in an anisotropic triangular lattice as a function of frustration and doping. This tunable lattice can be combined with a digital micromirror device to explore novel quantum phases in decorated lattice geometries. The dynamical tunability also facilitates full spin- and density- resolved imaging, as well as adiabatic state preparation of low entropy strongly correlated quantum phases.