Selective trapping of hexagonally warped topological surface states in a triangular quantum corral

Mu Chen; Ye-Ping Jiang; Junping Peng; Huimin Zhang; Cui-Zu Chang; Xiao Feng; Zhenguo Fu; Fawei Zheng; Ping Zhang; Lili Wang; Ke He; Xu-Cun Ma; Qi-Kun Xue

doi:10.1126/sciadv.aaw3988

Selective trapping of hexagonally warped topological surface states in a triangular quantum corral

Sci Adv. 2019 May 17;5(5):eaaw3988. doi: 10.1126/sciadv.aaw3988. eCollection 2019 May.

Authors

Mu Chen^{1

2}, Ye-Ping Jiang³, Junping Peng¹, Huimin Zhang¹, Cui-Zu Chang^{1

4}, Xiao Feng¹, Zhenguo Fu⁵, Fawei Zheng⁵, Ping Zhang⁵, Lili Wang^{1

6}, Ke He^{1

6}, Xu-Cun Ma^{1

6}, Qi-Kun Xue^{1

6

7}

Affiliations

¹ Department of Physics, Tsinghua University, Beijing 100084, China.
² Beijing Institute of Aeronautical Materials, Beijing 100095, China.
³ Key Laboratory of Polar Materials and Devices (MOE), Department of Optoelectronics, East China Normal University, Shanghai 200241, China.
⁴ Department of Physics, Pennsylvania State University, University Park, PA 16802, USA.
⁵ Institute of Applied Physics and Computational Mathematics, Beijing 100088, China.
⁶ Collaborative Innovation Center of Quantum Matter, Beijing 100084, China.
⁷ Beijing Academy of Quantum Information Sciences, Beijing 100193, China.

Abstract

The surface of a three-dimensional topological insulator (TI) hosts two-dimensional massless Dirac fermions (DFs), the gapless and spin-helical nature of which leads to their high transmission through surface defects or potential barriers. Here, we report the behaviors of topological surface states (TSS) in a triangular quantum corral (TQC) which, unlike a circular corral, is supposed to be totally transparent for DFs. By real-space mapping of the electronic structure of TQCs, both the trapping and detrapping behaviors of the TSS are observed. The selection rules are found to be governed by the geometry and spin texture of the constant energy contour of TSS upon the strong hexagonal warping in Bi₂Te₃. Our work indicates the extended nature of TSS and elucidates the selection rules of the trapping of TSS in the presence of a complicated surface state structure, giving insights into the effective engineering of DFs in TIs.