title: Observation of possible topological in-gap surface states in the Kondo insulator SmB6 by photoemission.
abstract: SmB6, a well-known Kondo insulator, exhibits a transport anomaly at low temperature. This anomaly is usually attributed to states within the hybridization gap. Recent theoretical work and transport measurements suggest that these in-gap states could be ascribed to topological surface states, which would make SmB6 the first realization of topological Kondo insulator. Here by performing angle-resolved photoemission spectroscopy experiments, we directly observe several dispersive states within the hybridization gap of SmB6. These states show negligible kz dependence, which indicates their surface origin. Furthermore, we perform photoemission circular dichroism experiments, which suggest that the in-gap states possess chirality of the orbital angular momentum. These states vanish simultaneously with the hybridization gap at around 150 K. Together, these observations suggest the possible topological origin of the in-gap states.
authors.affiliation: 1] State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China [2].
authors.forename: J
authors.initials: J
authors.lastname: Jiang
authors.affiliation: 1] National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China [2].
authors.forename: S
authors.initials: S
authors.lastname: Li
authors.affiliation: 1] State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China [2].
authors.forename: T
authors.initials: T
authors.lastname: Zhang
authors.affiliation: 1] Department of Physics, University of Science and Technology of China, Hefei 230026, China [2] National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Hefei National Laboratory for Physical Science at Microscale, University of Science and Technology of China, Hefei 230026, China.
authors.forename: F
authors.initials: F
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
authors.forename: Z R
authors.initials: ZR
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
authors.forename: M
authors.initials: M
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
authors.forename: Q Q
authors.initials: QQ
authors.lastname: Ge
authors.affiliation: State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
authors.forename: S Y
authors.initials: SY
authors.lastname: Tan
authors.affiliation: State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
authors.forename: X H
authors.initials: XH
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
authors.forename: M
authors.initials: M
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
authors.forename: B P
authors.initials: BP
authors.lastname: Xie
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Y F
authors.initials: YF
authors.lastname: Li
authors.affiliation: 1] Department of Physics, University of Science and Technology of China, Hefei 230026, China [2] Hefei National Laboratory for Physical Science at Microscale, University of Science and Technology of China, Hefei 230026, China.
authors.forename: X H
authors.initials: XH
authors.lastname: Chen
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: H H
authors.initials: HH
authors.lastname: Wen
authors.affiliation: State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China.
authors.forename: D L
authors.initials: DL
authors.lastname: Feng