title: Quantum oscillations in a two-dimensional electron gas in black phosphorus thin films.
abstract: For decades, two-dimensional electron gases (2DEG) have allowed important experimental discoveries and conceptual developments in condensed-matter physics. When combined with the unique electronic properties of two-dimensional crystals, they allow rich physical phenomena to be probed at the quantum level. Here, we create a 2DEG in black phosphorus--a recently added member of the two-dimensional atomic crystal family--using a gate electric field. The black phosphorus film hosting the 2DEG is placed on a hexagonal boron nitride substrate. The resulting high carrier mobility in the 2DEG allows the observation of quantum oscillations. The temperature and magnetic field dependence of these oscillations yields crucial information about the system, such as cyclotron mass and lifetime of its charge carriers. Our results, coupled with the fact that black phosphorus possesses anisotropic energy bands with a tunable, direct bandgap, distinguish black phosphorus 2DEG as a system with unique electronic and optoelectronic properties.
authors.affiliation: 1] State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Likai
authors.initials: L
authors.lastname: Li
authors.affiliation: 1] Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China [2] Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China [3] Hefei National Laboratory for Physical Science at Microscale and Department of 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 and Institute of Materials Science and Engineering, Washington University in St Louis, St Louis, Missouri 63136, USA.
authors.forename: Vy
authors.initials: V
authors.lastname: Tran
authors.affiliation: Department of Physics and Institute of Materials Science and Engineering, Washington University in St Louis, St Louis, Missouri 63136, USA.
authors.forename: Ruixiang
authors.initials: R
authors.lastname: Fei
authors.affiliation: 1] State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Guorui
authors.initials: G
authors.lastname: Chen
authors.affiliation: International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
authors.forename: Huichao
authors.initials: H
authors.lastname: Wang
authors.affiliation: International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan.
authors.forename: Kenji
authors.identifier: 0000000337018119
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: Department of Physics and Institute of Materials Science and Engineering, Washington University in St Louis, St Louis, Missouri 63136, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.affiliation: 1] Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China [2] Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China [3] Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Xian Hui
authors.initials: XH
authors.lastname: Chen
authors.affiliation: 1] State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China [2] Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Zhang