近日，美国普林斯顿大学的M. Zahid Hasan&Md Shafayat Hossain及其研究团队取得一项新进展。经过不懈努力，他们揭示拓扑铰链模式的量子输运响应。相关研究成果已于2024年2月20日在国际知名学术期刊《自然—物理学》上发表。
该研究为α-Bi4Br4内禀拓扑绝缘体和表面能隙中存在无能隙拓扑铰链态的量子输运提供了证据。通过磁阻测量，研究人员观察到了明显的Aharonov–Bohm振荡，其周期性精确地符合h/e（h为普朗克常数，e为电子电荷）。这一周期性现象证实了电子围绕铰链的量子干涉行为。研究人员还证明了h/e振荡随着磁场方向的函数演化，遵循拓扑和对称性允许的铰链模式的干涉路径。
这一研究发现揭示了具有拓扑性质和量子相干性的拓扑铰链模式的量子输运响应，这最终可以应用于高效拓扑电子器件的开发。
据悉，电子拓扑相由存在于绝缘三维体边界上的导电表面态来表征。虽然二维表面态的输运响应已经被研究过，但一维铰链模式的量子响应还没有被证明。
附：英文原文
Title: Quantum transport response of topological hinge modes
Author: Hossain, Md Shafayat, Zhang, Qi, Wang, Zhiwei, Dhale, Nikhil, Liu, Wenhao, Litskevich, Maksim, Casas, Brian, Shumiya, Nana, Yin, Jia-Xin, Cochran, Tyler A., Li, Yongkai, Jiang, Yu-Xiao, Zhang, Yuqi, Cheng, Guangming, Cheng, Zi-Jia, Yang, Xian P., Yao, Nan, Neupert, Titus, Balicas, Luis, Yao, Yugui, Lv, Bing, Hasan, M. Zahid
Issue&Volume: 2024-02-20
Abstract: Electronic topological phases are typified by the conducting surface states that exist on the boundary of an insulating three-dimensional bulk. While the transport response of the two-dimensional surface states has been studied, the quantum response of the one-dimensional hinge modes has not been demonstrated. Here we provide evidence for quantum transport in gapless topological hinge states existing within the insulating bulk and surface energy gaps in the intrinsic topological insulator α-Bi4Br4. Our magnetoresistance measurements reveal pronounced Aharonov–Bohm oscillations that are periodic in h/e (where h denotes Planck’s constant and e is the electron charge). The observed periodicity evinces quantum interference of electrons circumnavigating around the hinges. We also demonstrate that the h/e oscillations evolve as a function of magnetic field orientation, following the interference paths along the hinge modes that are allowed by topology and symmetry. Our findings reveal the quantum transport response of topological hinge modes with both topological nature and quantum coherence, which can eventually be applied to the development of efficient topological electronic devices.
DOI: 10.1038/s41567-024-02388-1
Source: https://www.nature.com/articles/s41567-024-02388-1