Bose Hubbard Models with Synthetic Spin-Orbit Coupling: Mott Insulators, Spin Textures and Superfluidity

TL;DR

This paper explores the phase diagram of the Bose Hubbard model with synthetic spin-orbit coupling, revealing exotic magnetic textures in Mott insulators and their influence on superfluid phases, with potential experimental signatures.

Contribution

It introduces a comprehensive analysis of magnetic textures and superfluid orders in Bose Hubbard models with synthetic spin-orbit coupling, combining strong coupling expansion, mean field, and slave boson theories.

Findings

Magnetic textures like spin spirals, vortices, and Skyrmion crystals emerge in Mott insulators.

Superfluid phases inherit magnetic orders and show modulated current patterns.

Experimental signatures include Bragg scattering, microscopy, and quench dynamics.

Abstract

Motivated by the experimental realization of synthetic spin-orbit coupling for ultracold atoms, we investigate the phase diagram of the Bose Hubbard model in a non-abelian gauge field in two dimensions. Using a strong coupling expansion in the combined presence of spin-orbit coupling and tunable interactions, we find a variety of interesting magnetic Hamiltonians in the Mott insulator (MI), which support magnetic textures such as spin spirals and vortex and Skyrmion crystals. An inhomogeneous mean field treatment shows that the superfluid (SF) phases inherit these exotic magnetic orders from the MI and display, in addition, unusual modulated current patterns. We present a slave boson theory which gives insight into such intertwined spin-charge orders in the SF, and discuss signatures of these orders in Bragg scattering, in situ microscopy, and dynamic quench experiments.