Synthetic spin-orbit coupling for the multispin models in optical lattices

TL;DR

This paper introduces a general method to engineer synthetic spin-orbit coupling in multispin models using cold atoms, enabling exploration of topological phases with high Chern numbers.

Contribution

A novel, straightforward approach to realize spin-orbit coupling in multispin models, facilitating topological phase transitions with large Chern numbers.

Findings

Achieved spin-orbit coupling with direction-dependent strength.

Enabled topological phase transitions with Chern numbers over 1.

Provided a platform for studying topological properties in large-Chern-number systems.

Abstract

The essential role of synthetic spin-orbit coupling in discovering new topological matter phases with cold atoms is widely acknowledged. However, the engineering of spin-orbit coupling remains unclear for arbitrary-spin models due to the complexity of spin matrices. In this paper, we develop a more general but relatively straightforward method to achieve spin-orbit coupling for multispin models. Our approach hinges on controlling the coupling between distinct pseudo-spins through two intermediary states, resulting in tunneling with spin flips that have direction-dependent strength. The engineered spin-orbit coupling can facilitate topological phase transitions with Chern numbers over 1, a unique characteristic of multispin models compared to spin-1/2 models. By utilizing existing cold atom techniques, our proposed method provides an ideal platform for investigating topological properties related to large Chern numbers.