Abstract

Light-induced spin-orbit coupling is a flexible tool to study quantum magnetism with ultracold atoms. In this work we show that spin-orbit coupled Bose gases in a one-dimensional optical lattice can be mapped into a two-leg triangular ladder with staggered flux following a lowest-band truncation of the Hamiltonian. The effective flux and the ratio of the tunneling strengths can be independently adjusted to a wide range of values. We identify a certain regime of parameters where a hard-core boson approximation holds and the system realizes a frustrated triangular spin ladder with tunable flux. We study the properties of the effective spin Hamiltonian using the density-matrix renormalization-group method and determine the phase diagram at half-filling. It displays two phases: a uniform superfluid and a bond-ordered insulator. The latter can be stabilized only for low Raman detuning. Finally, we provide experimentally feasible trajectories across the parameter space of the SOC system that cross the predicted phase transition.

Graphical abstract

中文翻译：

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一维光学晶格中自旋轨道耦合产生的具有交错通量的有效三角阶梯

摘要

光诱导的自旋轨道耦合是研究超冷原子的量子磁性的灵活工具。在这项工作中，我们证明了在一维光学晶格中自旋轨道耦合的玻色气体可以被映射成哈密顿量的最低频带截断后具有交错通量的两腿三角阶梯。有效通量和隧穿强度的比率可以独立地调整到较大的值范围。我们确定了某种特定的参数体系，其中硬核玻色近似保持不变，并且系统实现了具有可调通量的受挫三角形自旋阶梯。我们使用密度矩阵重归一化群方法研究有效自旋哈密顿量的性质，并确定半填充时的相图。它显示两个阶段：均匀的超流体和有序的绝缘体。后者仅在低拉曼失谐时才能稳定。最后，我们提供了跨越SOC系统参数空间且跨过预测相变的实验可行轨迹。

图形概要