Non-Abelian dynamical gauge field and topological superfluids in optical Raman lattice

Abstract

We propose an experimental scheme to realize non-Abelian dynamical gauge field for ultracold fermions, which induces a novel pairing mechanism of topological superfluidity. The dynamical gauge fields arise from nontrivial interplay effect between the strong Zeeman splitting and Hubbard interaction in a two-dimensional (2D) optical Raman lattice. The spin-flip transitions are forbidden by the large Zeeman detuning, but are restored when the Zeeman splitting is compensated by Hubbard interaction. This scheme allows to generate a dynamical non-Abelian gauge field that leads to a Dirac type correlated 2D spin-orbit interaction depending on local state configurations. The topological superfluid from a novel pairing driven by 2D dynamical gauge fields is reached, with analytic and numerical results being obtained. Our work may open up a door to emulate non-Abelian dynamical gauge fields and correlated topological phases with experimental feasibility.