近日，南京大学的Jian-Te Wang与华南师范大学的朱诗亮合作并取得一项新进展。他们提出在光学晶格中实现和探测拓扑晶体绝缘体的方案。相关研究成果已于2024年12月11日在国际知名学术期刊《物理评论A》上发表。

该研究团队通过引入额外的自旋-轨道耦合项，开发了一个晶格模型，该模型展现出从Z₂拓扑绝缘体到受镜像对称性保护的拓扑晶体绝缘体的拓扑相变。拓扑相由镜像缠绕数表征，该数在镜像对称性不变的子空间中定义，确保了特定边界条件下无带隙边缘态和零能角态的保护。

此外，研究人员提出了一种可行的方案，利用被限制在堆叠六边形光学晶格中的超冷原子，以及拉曼场来实现二维拓扑晶体绝缘体。在这些系统中，可以通过实施一个简单的淬火序列，并观察飞行时间模式的演化来检测镜像缠绕数。

附：英文原文

Title: Proposal for realizing and probing topological crystalline insulators in optical lattices

Author: Jing-Xin Liu, Jian-Te Wang, Shi-Liang Zhu

Issue&Volume: 2024/12/11

Abstract: We develop a lattice model which exhibits topological transitions from Z₂ topological insulators to mirror-symmetry-protected topological crystalline insulators by introducing additional spin-orbit coupling terms. The topological phase is characterized by the mirror winding number, defined within the mirror-symmetry-invariant subspace, which ensures the protection of gapless edge states and zero-energy corner states under specific boundary conditions. Additionally, we propose a feasible scheme using ultracold atoms confined in a stacked hexagonal optical lattice with Raman fields to realize the two-dimensional topological crystalline insulators. Detection of the mirror winding number in these systems can be achieved by implementing a simple quench sequence and observing the evolution of the time-of-flight patterns.

DOI: 10.1103/PhysRevA.110.063309

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.063309