We propose a novel geometric model of three-dimensional topological insulators in presence of an external electromagnetic field. The gapped boundary of these systems supports relativistic quantum Hall states and is described by a Chern-Simons theory with a gauge connection that takes values in the Maxwell algebra. This represents a non-central extension of the Poincaré algebra and takes into account both the Lorentz and magnetic-translation symmetries of the surface states. In this way, we derive a relativistic version of the Wen-Zee term, and we show that the non-minimal coupling between the background geometry and the electromagnetic field in the model is in agreement with the main properties of the relativistic quantum Hall states in the flat space.
Fundamental Tests of Quantum Geometric Bounds in Ionic and Covalent Insulators using Inelastic X-Ray Scattering
University of Illinois（伊利诺伊大学）；Anthony J Leggett Institute for Condensed Matter Theory, University of Illinois（伊利诺伊大学安东尼·J·雷格特凝聚态理论研究所）；Astera Institute（阿斯特拉研究所）；Materials Research Laboratory, University of Illinois（伊利诺伊大学材料研究实验室）
Interferometric Braiding of Anyons in Chern Insulators
Ludwig-Maximilians-Universität München（慕尼黑大学）；Munich Center for Quantum Science and Technology (MCQST)（慕尼黑量子科学与技术中心）；Université Libre de Bruxelles（布鲁塞尔自由大学）；Collège de France（法兰西公学院）；Sorbonne Université（索邦大学）；International Solvay Institutes（国际索尔维研究所）
Demonstration of Robust Chiral Edge Transport in Field-Induced Chern Insulator MnBi2Te4 Devices with Engineered Geometric Defects
International Center for Quantum Materials, School of Physics, Peking University（北京大学物理学院量子材料国际中心）；Beijing Key Laboratory of Quantum Devices, Peking University（北京大学北京量子器件重点实验室）；State Key Laboratory of Quantum Functional Materials, and ShanghaiTech Laboratory for Topological Physics, School of Physical Science and Technology, ShanghaiTech University（上海科技大学物理科学与技术学院量子功能材料国家重点实验室及拓扑物理上海科技大学实验室）；National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Advanced Manufacturing Engineering, Nanjing University（南京大学先进微结构协同创新中心固体微观结构国家重点实验室先进制造工程学院）；National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University（南京大学固体微观结构国家重点实验室先进微结构协同创新中心物理学院）；Atom Manufacturing Institute（原子制造研究所）；Hefei National Laboratory（合肥国家实验室）；Collaborative Innovation Center of Quantum Matter（量子物质协同创新中心）
Observation of the universal magnetoelectric effect in a 3D topological insulator
拓扑绝缘体（TI）的电动力学由修改的麦克斯韦方程描述，其包含将电场耦合到介质的磁化和将磁场耦合到介质的极化的附加项，使得耦合系数被量化为每个表面$e^2 / 2 h c $的奇数倍。在这里，我们报告观察到的这种所谓的拓扑磁电（TME）效应。我们使用单色太赫兹（THz）光谱的TI结构配备了半透明的门选择性地解决表面状态。在强外磁场中，当一定频率的线偏振太赫兹辐射通过应变碲化汞三维薄膜的两个表面时，我们观察到一个与精细结构常数$α= e^2 / \hbar c$相等的普遍法拉第旋转角.这些实验提供了对TI的轴子电动力学的深入了解，并可能用于三个基本物理常数的精确定义。
