Spin Orbit Coupling in Periodically Driven Optical Lattices

8 July 2014

Photo: AG Sengstock

We propose a novel experimental scheme for the emulation of spin-orbit coupling for ultracold, neutral atoms trapped in a one-dimensional lattice. This scheme does not involve near-resonant laser fields, avoiding the heating processes connected to the spontaneous emission of photons.

A time dependent magnetic field gradient periodically drives the atoms, which can lead to complex valued tunnel matrix elements, equivalent to a gauge dependent shift of the dispersion relation for a 1D lattice. For opposite spin states, the dispersion relations are shifted in opposite direction due to the inverted drive for both states. An additional radio-frequency coupling between the spin states leads to a mixing of the spin dispersion relations and a spin-orbit gap in the band structure.

Phys. Rev. A 90, 031601(R) (2014)