title: Identification of helicity-dependent photocurrents from topological surface states in Bi2Se3 gated by ionic liquid.
abstract: Dirac-like surface states on surfaces of topological insulators have a chiral spin structure with spin locked to momentum, which is interesting in physics and may also have important applications in spintronics. In this work, by measuring the tunable helicity-dependent photocurrent (HDP), we present an identification of the HDP from the Dirac-like surface states at room temperature. It turns out that the total HDP has two components, one from the Dirac-like surface states, and the other from the surface accumulation layer. These two components have opposite directions. The clear gate tuning of the electron density as well as the HDP signal indicates that the surface band bending and resulted surface accumulation are successfully modulated by the applied ionic liquid gate, which provides a promising way to the study of the Dirac-like surface states and also potential applications in spintronic devices.
authors.affiliation: State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Junxi
authors.initials: J
authors.lastname: Duan
authors.affiliation: State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: He
authors.affiliation: State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Shan
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences(CAS), Beijing 100083, People's Republic of China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Qin
authors.affiliation: 1] State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China [2] Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China.
authors.forename: Xinqiang
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Xuelin
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Fujun
authors.initials: F
authors.lastname: Xu
authors.affiliation: Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences(CAS), Beijing 100083, People's Republic of China.
authors.forename: Yonghai
authors.initials: Y
authors.lastname: Chen
authors.affiliation: 1] State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China [2] Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Weikun
authors.initials: W
authors.lastname: Ge
authors.affiliation: 1] State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China [2] Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Shen