title: Gate-tuned quantum oscillations of topological surface states in β-Ag2Te.
abstract: We report the strong experimental evidence of the existence of topological surface states with large electric field tunability and mobility in β-Ag2Te. Pronounced 2D Shubnikov-de Haas oscillations have been observed in β-Ag2Te nanoplates. A Berry phase is determined to be near π using the Landau level fan diagram for a relatively wide nanoplate while the largest electric field ambipolar effect in topological insulator so far (~2500%) is observed in a narrow nanoplate. The π Berry phase and the evolution of quantum oscillations with gate voltage (Vg) in the nanoplates strongly indicate the presence of topological surface states in β-Ag2Te. Moreover, the mobility of the narrow Ag2Te nanoplate is about several thousand cm(2)s(-1)V(-1). Our results suggest that β-Ag2Te has the potential to become an important material in the investigation of topological insulators.
authors.affiliation: School of Physical and Mathematical Sciences, Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371.
authors.forename: Azat
authors.initials: A
authors.lastname: Sulaev
authors.affiliation: School of Electronics and Electrical Engineering, Nanyang Technological University, Singapore 639789.
authors.forename: Weiguang
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576.
authors.forename: Kie Leong
authors.initials: KL
authors.lastname: Teo
authors.affiliation: 1] School of Physical and Mathematical Sciences, Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371 [2] School of Applied Sciences, RMIT University, Melbourne, VIC 3000, Australia.
authors.forename: Lan
authors.initials: L
authors.lastname: Wang