Topological lattice using multi-frequency radiation
We describe a novel technique for creating an artificial magnetic field for ultracold atoms using a periodically pulsed pair of counter propagating Raman lasers that drive transitions between a pair of internal atomic spin states: a multi-frequency coupling term. In conjunction with a magnetic field gradient, this dynamically generates a rectangular lattice with a non-staggered magnetic flux. For a wide range of parameters, the resulting Bloch bands have non-trivial topology, reminiscent of Landau levels, as quantified by their Chern numbers.
Topological lattice using multi-frequency radiation; Andrijauskas, I. B. Spielman, and G. Juzeliūnas; New Journal of Physics 20 055001 (2018). doi:10.1088/1367-2630/aab7a3