FeTe1-xSex monolayer films: towards the realization of high-temperature connate topological superconductivity

Xun Shi; Zhi-Qing Han; Pierre Richard; Xian-Xin Wu; Xi-Liang Peng; Tian Qian; Shan-Cai Wang; Jiang-Ping Hu; Yu-Jie Sun; Hong Ding

doi:10.1016/j.scib.2017.03.010

FeTe_1-_xSe_x monolayer films: towards the realization of high-temperature connate topological superconductivity

Sci Bull (Beijing). 2017 Apr 15;62(7):503-507. doi: 10.1016/j.scib.2017.03.010. Epub 2017 Mar 9.

Authors

Xun Shi¹, Zhi-Qing Han², Pierre Richard³, Xian-Xin Wu¹, Xi-Liang Peng¹, Tian Qian⁴, Shan-Cai Wang⁵, Jiang-Ping Hu³, Yu-Jie Sun⁶, Hong Ding⁷

Affiliations

¹ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
² Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Department of Physics, Beijing Key Laboratory of Opto-Electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, China.
³ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Collaborative Innovation Center of Quantum Matter, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China.
⁴ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Collaborative Innovation Center of Quantum Matter, Beijing 100190, China.
⁵ Department of Physics, Beijing Key Laboratory of Opto-Electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, China.
⁶ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: yjsun@iphy.ac.cn.
⁷ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Collaborative Innovation Center of Quantum Matter, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China. Electronic address: dingh@iphy.ac.cn.

PMID: 36659260
DOI: 10.1016/j.scib.2017.03.010

Abstract

We performed angle-resolved photoemission spectroscopy studies on a series of FeTe_1-_xSe_x monolayer films grown on SrTiO₃. The superconductivity of the films is robust and rather insensitive to the variations of the band position and effective mass caused by the substitution of Se by Te. However, the band gap between the electron- and hole-like bands at the Brillouin zone center decreases towards band inversion and parity exchange, which drive the system to a nontrivial topological state predicted by theoretical calculations. Our results provide a clear experimental indication that the FeTe_1-_xSe_x monolayer materials are high-temperature connate topological superconductors in which band topology and superconductivity are integrated intrinsically.

Keywords: Iron-based superconductors; Thin film; Topological superconductivity.