Use of quantum quenches to probe the equilibrium current patterns of ultracold atoms in an optical lattice

Atomic bosons and fermions in an optical lattice can realize various condensed-matter states that support equilibrium current patterns in the presence of synthetic magnetic fields or non-Abelian gauge fields. As a route to probing such mass currents, we propose a nonequilibrium quantum quench of the Hamiltonian that dynamically converts the current patterns into experimentally measurable real-space density patterns. We illustrate how a specific such "unidirectional" quench of the optical lattice can be used to uncover bulk checkerboard and stripe current orders in lattice Bose superfluids and Fermi gases, as well as chiral edge currents in a quantum Hall state.