光晶格中多组分自旋轨道耦合偶极玻色气体新奇量子相的研究

The spin-orbit coupling and the dipole-dipole interaction induce a rich variety of quantum phases in Bose gases in optical lattices, such as supersolid phase, plane wave phase and stripe phase, the study on spin-orbit coupled dipolar Bose gases in optical lattices becomes the hot topic of the ultracold atomic physics at the present time. Although some progress has been made in studying of spin-orbit coupled dipolar Bose gases in optical lattices in recent years, these studies mainly focus on the two-component Bose gases. However, studies on ground-state phases of multicomponent Bose gases not usually seen. The spin-orbit coupled dipolar Bose gases in optical lattices have a great research value, it attracts much attention recently.The project intends to study the novel quantum phases of multicomponent spin-orbit coupled dipolar Bose gases in optical lattices, including: (1) we will investigate the phase transition from the Mott phase to the supersolid phase, and to the superfluid phase; (2) we will use the quantum perturbation theory to obtain the Hamiltonian of an effective spin model in the Mott regime, and use the variational method to investigate the ground-state phases in the Mott insulator, supersolid and superfluid regimes; (3) we will investigate the realization mechanism of supersolid phase and propose the experimental observation scheme. These studies are interesting, which will not only deepen our understanding the novel quantum phases of multicomponent spin-orbit coupled dipolar Bose gases in optical lattices but also provide theoretical basis for constructing new quantum magnetic material with topological singularity.

自旋轨道耦合作用和偶极-偶极相互作用可以使光晶格中玻色气体产生丰富的量子相，如超固相、平面波相和条纹相等，因此光晶格中自旋轨道耦合偶极玻色气体的研究成为当前冷原子物理的热点问题。尽管近些年来人们在该课题的研究方面取得了一些成果，但主要针对两组分玻色气体，而对于多组分玻色气体，其基态方面的研究工作还不是很多。本项目拟研究光晶格中多组分自旋轨道耦合偶极玻色气体新奇量子相。主要内容包括：(1)探究系统从Mott绝缘相到超固相以及超流相的相变；(2)推导Mott绝缘区有效量子自旋模型的哈密顿量，基于变分法获得Mott绝缘区、超固区以及超流区的基态相；(3)探究超固相的实现机理，提出实验观测方案。本项研究不仅加深对光晶格中多组分自旋轨道耦合偶极玻色气体新奇量子相的认识和理解，还可以为构建具有奇异拓扑性质的新型量子磁性材料提供理论基础，有着重要的科学意义。

本项目主要研究自旋轨道耦合旋量玻色气体中各类新奇基态及其拓扑激发特性。在该项目资助下，主要完成的工作如下：(1)在旋转自旋轨道耦合自旋-1/2玻色气体研究中，发现了空间调制的非线性自旋轨道耦合不仅能提升涡旋链相的的形成而且还保护了该相的稳定性，为实验上观测提供了可能；(2)在SU(3)自旋轨道耦合自旋-1玻色气体中，SU(3)自旋轨道耦合和自旋交换作用共同作用实现了多种类型的超固相，为在自旋轨道耦合玻色气体中研究超固相的实现机理提供了理论基础；(3)利用虚实演化的方法研究了自旋轨道耦合旋量玻色气体囚禁在光晶格中基态相图。通过对不同类型基态相的系统分析，揭示了这些基态相的形成机制，为将来实验上的实现提供了理论指导；(4)与合作者开发了一种基于数据压缩的神经网络算法研究了AA模型(Aubry-Andre model)单粒子迁移边缘和相变，也证明此方法适用于探究光晶格系统的量子相变和多体局域等现象，同时我们也利用严格对角化方法和Guztwiller方法对自旋轨道耦合玻色-哈伯德模型，四链玻色-哈伯德模型研究了相位相干性及其相变进行研究，实现了利用简单模型定性的分析了复杂的自旋轨道耦合玻色-哈伯德模型的相变过程。研究结果不仅有助于进一步确定了关键物理量对自旋轨道旋量玻色气体基态相的影响，同时也加深了对自旋轨道耦合气体中实现超固相的物理机制的理解。