Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
J Phys Condens Matter. 2023 Mar 27;35(23). doi: 10.1088/1361-648X/acc3eb.
BiBris 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 BiBrnanobelts. 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 BiBr.
BiB 是一种准一维范德瓦尔斯拓扑绝缘体，具有新颖的电子特性。人们已经做出了许多努力来理解其体相形式，但由于器件制造的困难，探索其低维结构中的输运性质仍然是一个挑战。在这里，我们首次报道了在剥离的 BiBr 纳米带中可栅控的输运性质。在低温下发现了显著的双频舒布尼科夫-德哈斯振荡，低频和高频部分分别来自三维体相和二维表面相。此外，通过纵向电阻峰和霍尔系数的符号反转实现了双极性场效应。我们成功地测量了量子振荡并实现了栅控输运，为进一步研究 BiBr 中的新型拓扑性质和室温量子自旋霍尔态奠定了基础。
