Density-Dependent Gauge Field with Raman Lattices

The study of the gauge field is an everlasting topic in modern physics. Spin-orbit coupling is a powerful tool in ultracold atomic systems, resulting in an artificial gauge field that can be easily manipulated and observed in a tabletop environment. Combining optical lattices and atom-atom interaction, the artificial gauge field can be made density-dependent. In this work, we investigate a one-dimensional Bose-Hubbard model with spin-orbit coupling, where a density-dependent gauge field emerges spontaneously in low-energy physics. First, we focus on the two-body quantum walk dynamics and give an interpretation of the phenomena with resonant tunneling. Then, we calculate the mean-field phase diagram using the two-site Gutzwiller ansatz. Two types of superfluid phase and a Mott insulator phase are found. Finally, we discuss the experimental realization protocol with Raman lattices.