title: Quantum Hall effect in black phosphorus two-dimensional electron system.
abstract: The development of new, high-quality functional materials has been at the forefront of condensed-matter research. The recent advent of two-dimensional black phosphorus has greatly enriched the materials base of two-dimensional electron systems (2DESs). Here, we report the observation of the integer quantum Hall effect in a high-quality black phosphorus 2DES. The high quality is achieved by embedding the black phosphorus 2DES in a van der Waals heterostructure close to a graphite back gate; the graphite gate screens the impurity potential in the 2DES and brings the carrier Hall mobility up to 6,000 cm(2) V(-1) s(-1). The exceptional mobility enabled us to observe the quantum Hall effect and to gain important information on the energetics of the spin-split Landau levels in black phosphorus. Our results set the stage for further study on quantum transport and device application in the ultrahigh mobility regime.
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Likai
authors.initials: L
authors.lastname: Li
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Fangyuan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.|Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Guo Jun
authors.initials: GJ
authors.lastname: Ye
authors.affiliation: Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Zuocheng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Zengwei
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Wenkai
authors.identifier: 0000-0001-6906-6479
authors.initials: W
authors.lastname: Lou
authors.affiliation: SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.affiliation: Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan.
authors.forename: Kenji
authors.identifier: 0000-0003-3701-8119
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Taniguchi
authors.affiliation: SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Chang
authors.affiliation: Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Yayu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.|Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Xian Hui
authors.initials: XH
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.|Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Zhang