Quantum transport response of topological hinge modes

• Published in: Nature physics 2024-05, Vol.20 (5), p.776-782
• Main Authors: 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
• Format: Article
• Language: English
• Subjects: 639/301/119/995; 639/766/119/2792/4128; Aharonov-Bohm effect; Atomic; Classical and Continuum Physics; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Coherence; Complex Systems; Condensed Matter Physics; Electron transport; Electronic devices; Electronic properties and materials; Electrons; Energy gap; Fourier transforms; Higher order topological insulators; Insulation; Interference; Magnetic fields; Magnetoresistance; Magnetoresistivity; Mathematical and Computational Physics; Microscopy; Molecular; Optical and Plasma Physics; Oscillations; Physics; Physics and Astronomy; Quantum phenomena; Quantum transport; Surface energy; Symmetry; Theoretical; Topological insulators; Topology
• ISSN: 1745-2473; 1745-2481
• DOI: 10.1038/s41567-024-02388-1

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-Bi 4 Br 4 . 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. Topologically protected hinge modes could be important for developing quantum devices, but electronic transport through those states has not been demonstrated. Now quantum transport has been shown in gapless topological hinge states.