The beauty of quantum Hall (QH) effect is the metrological precision of Hall resistance quantization that originates from the topological edge states. Understanding the factors that lead to quantization breakdown not only provides important insights on the nature of the topological protection of these edge states, but is beneficial for device applications involving such quantized transport. In this work, we combine conventional transport and real space conductivity mapping to investigate whether the quantization breakdown is tied to the disappearance of edge state in the hotly studied MnBi2Te4 system. Our experimental results unambiguously show that topological edge state does exist when quantization breakdown occurs. Such edge state is dissipative in nature and could lead to a quantization breakdown due to its diffusive character causing overlapping with bulk and other edge states in real devices. Our findings bring attentions to issues that are generally inaccessible in the transport study of QH, but can play important roles in practical measurements and device applications.
Anomalous Edge Transport in the Quantum Anomalous Hall State
通过第一性原理计算，我们预测了Cr掺杂（Bi，Sb）$_2$ Te $_3$磁性拓扑绝缘体薄膜具有与手征边缘态共存的无带隙非手征边缘态.这种无间隙的非手性态不能免疫于背散射，这将解释在该系统中实验观察到的量子反常霍尔（QAH）态中的耗散输运。本文利用Landau-Büttiker方法研究了手征态和非手征态的边缘输运，发现纵向电阻不为零，而霍尔电阻量子化为$h/e^2$ .特别是，纵向电阻可以大大减少增加一个额外的浮动探针，即使它不使用，而霍尔电阻保持在量化值。我们提出了几个传输实验来检测耗散的非手征边缘通道。这些结果将有助于实现QAH态在磁性拓扑绝缘体中的纯无耗散输运。
Controlling Quantum Transport in a Superconducting Device via Dissipative Baths
L. D. Landau Institute for Theoretical Physics（列夫·朗道理论物理研究所）；Kirensky Institute of Physics, Federal Research Center KSC SB RAS（基连斯基物理研究所，俄罗斯科学院西伯利亚分院克拉斯诺亚尔斯克科学中心联邦研究中心）；Laboratory for Condensed Matter Physics, HSE University（高等经济大学凝聚态物理实验室）
A local quantized marker for topological magnons from circular dichroism
Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-Université PSL, Sorbonne Université（卡斯勒-布罗塞尔实验室，法兰西公学院，法国国家科学研究中心，巴黎高等师范学院-巴黎文理研究大学，索邦大学）；International Solvay Institutes（国际索尔维研究所）；Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles（非线性现象与复杂系统中心，布鲁塞尔自由大学）；Dynamic Quantum Materials Laboratory, Institute of Materials, EPFL（动态量子材料实验室，材料研究所，洛桑联邦理工学院）
Quantized Hall drift in a frequency-encoded photonic Chern insulator
Université de Montréal（蒙特利尔大学）；INO-CNR（意大利国家研究委员会光学研究所）；Università di Trento（特伦托大学）；Ecole Polytechnique（巴黎综合理工学院）；Institut Polytechnique de Paris（巴黎理工学院）；Advanced Institute for Materials Research (WPI-AIMR), Tohoku University（东北大学材料科学研究高等研究院）；Institut Courtois（库尔瓦研究所）
Energy-Resolved Quantum Geometry from Středa Response: Driven-Dissipative Bosonic Lattices and Disordered Systems
Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-Université PSL, Sorbonne Université（卡斯勒-布罗塞尔实验室，法兰西学院，法国国家科学研究中心，巴黎高等师范学院-巴黎文理研究大学，索邦大学）；International Solvay Institutes（国际索尔维研究所）；Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles（非线性现象与复杂系统中心，布鲁塞尔自由大学）
