title: Achieving Ultrahigh Carrier Mobility in Two-Dimensional Hole Gas of Black Phosphorus.
abstract: We demonstrate that a field-effect transistor (FET) made of few-layer black phosphorus (BP) encapsulated in hexagonal boron nitride (h-BN) in vacuum exhibits a room-temperature hole mobility of 5200 cm2/(Vs), being limited just by the phonon scattering. At cryogenic temperatures, the FET mobility increases up to 45 000 cm2/(Vs), which is five times higher compared to the mobility obtained in earlier reports. The unprecedentedly clean h-BN-BP-h-BN heterostructure exhibits Shubnikov-de Haas oscillations and a quantum Hall effect with Landau level (LL) filling factors down to v = 2 in conventional laboratory magnetic fields. Moreover, carrier density independent effective mass of m*= 0.26 m0is measured, and a Landé g-factor of g = 2.47 is reported. Furthermore, an indication for a distinct hole transport behavior with up- and down-spin orientations is found.
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Gen
authors.initials: G
authors.lastname: Long
authors.affiliation: RIKEN Center for Emergent Matter Science (CEMS) , Wako 351-0198, Japan.
authors.forename: Denis
authors.initials: D
authors.lastname: Maryenko
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Junying
authors.initials: J
authors.lastname: Shen
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Shuigang
authors.initials: S
authors.lastname: Xu
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Hou
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Zefei
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Wing Ki
authors.initials: WK
authors.lastname: Wong
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Tianyi
authors.initials: T
authors.lastname: Han
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Jiangxiazi
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Rolf
authors.initials: R
authors.lastname: Lortz
authors.affiliation: Department of Physics and Center for Quantum Materials, The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
keywords: Black phosphorus; Landau level coincidence; g-factor; mobility; quantum Hall effect; spin-selective transport