Gate-tunable transport in van der Waals topological insulator Bi4Br4 nanobelts. (14th June 2023)

• Record Type: Journal Article
• Authors: Wu, Si-Li; Ren, Zhi-Hui; Zhang, Yu-Qi; Li, Yong-Kai; Han, Jun-Feng; Duan, Jun-Xi; Wang, Zhi-Wei; Li, Cai-Zhen; Yao, Yu-Gui
• Is Part Of: Journal of physics. Volume 35:Number 23(2023)
• Publication Date: 2023-06-14
• Subjects: quasi-one-dimensional topological insulator -- Bi4Br4 -- Shubnikov–de Haas oscillations -- nanobelt -- gate-tunable transport; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/acc3eb
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Bi4 Br4 is a quasi-one-dimensional van der Waals topological insulator with novel electronic properties. Several efforts have been devoted to the understanding of its bulk form, yet it remains a challenge to explore the transport properties in low-dimensional structures due to the difficulty of device fabrication. Here we report for the first time a gate-tunable transport in exfoliated Bi4 Br4 nanobelts. Notable two-frequency Shubnikov–de Haas oscillations oscillations are discovered at low temperatures, with the low- and high-frequency parts coming from the three-dimensional bulk state and the two-dimensional surface state, respectively. In addition, ambipolar field effect is realized with a longitudinal resistance peak and a sign reverse in the Hall coefficient. Our successful measurements of quantum oscillations and realization of gate-tunable transport lay a foundation for further investigation of novel topological properties and room-temperature quantum spin Hall states in Bi4 Br4 .