Spin-orbit coupling and quantum spin Hall effect for neutral atoms without spin flips

Phys Rev Lett. 2013 Nov 27;111(22):225301. doi: 10.1103/PhysRevLett.111.225301. Epub 2013 Nov 25.

Abstract

We propose a scheme which realizes spin-orbit coupling and the quantum spin Hall effect for neutral atoms in optical lattices without relying on near resonant laser light to couple different spin states. The spin-orbit coupling is created by modifying the motion of atoms in a spin-dependent way by laser recoil. The spin selectivity is provided by Zeeman shifts created with a magnetic field gradient. Alternatively, a quantum spin Hall Hamiltonian can be created by all-optical means using a period-tripling, spin-dependent superlattice.