Discovery of Superconductivity in 2M WS2 with Possible Topological Surface States

Yuqiang Fang; Jie Pan; Dongqin Zhang; Dong Wang; Hishiro T Hirose; Taichi Terashima; Shinya Uji; Yonghao Yuan; Wei Li; Zhen Tian; Jiamin Xue; Yonghui Ma; Wei Zhao; Qikun Xue; Gang Mu; Haijun Zhang; Fuqiang Huang

doi:10.1002/adma.201901942

Discovery of Superconductivity in 2M WS₂ with Possible Topological Surface States

Adv Mater. 2019 Jul;31(30):e1901942. doi: 10.1002/adma.201901942. Epub 2019 Jun 3.

Authors

Yuqiang Fang^{1

2

3}, Jie Pan¹, Dongqin Zhang^{4

5}, Dong Wang¹, Hishiro T Hirose⁶, Taichi Terashima⁶, Shinya Uji⁶, Yonghao Yuan^{7

8}, Wei Li^{7

8}, Zhen Tian⁹, Jiamin Xue⁹, Yonghui Ma¹⁰, Wei Zhao¹, Qikun Xue^{7

8}, Gang Mu¹⁰, Haijun Zhang^{4

5}, Fuqiang Huang^{1

2}

Affiliations

¹ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, 200050, P. R. China.
² State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
³ University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
⁴ National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, P. R. China.
⁵ Collaborative Innovation Center of Advanced Microstructures, Nanjing, 210093, P. R. China.
⁶ National Institute for Materials Science, Tsukuba, Ibaraki, 305-0003, Japan.
⁷ State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, 100084, P. R. China.
⁸ Collaborative Innovation Center of Quantum Matter, Beijing, 100084, P. R. China.
⁹ School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, P. R. China.
¹⁰ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, P. R. China.

PMID: 31157482
DOI: 10.1002/adma.201901942

Abstract

Recently the metastable 1T'-type VIB-group transition metal dichalcogenides (TMDs) have attracted extensive attention due to their rich and intriguing physical properties, including superconductivity, valleytronics physics, and topological physics. Here, a new layered WS₂ dubbed "2M" WS₂ , is constructed from 1T' WS₂ monolayers, is synthesized. Its phase is defined as 2M based on the number of layers in each unit cell and the subordinate crystallographic system. Intrinsic superconductivity is observed in 2M WS₂ with a transition temperature T_c of 8.8 K, which is the highest among TMDs not subject to any fine-tuning process. Furthermore, the electronic structure of 2M WS₂ is found by Shubnikov-de Haas oscillations and first-principles calculations to have a strong anisotropy. In addition, topological surface states with a single Dirac cone, protected by topological invariant Z₂ , are predicted through first-principles calculations. These findings reveal that the new 2M WS₂ might be an interesting topological superconductor candidate from the VIB-group transition metal dichalcogenides.

Keywords: 2M WS2; superconductivity; topological surface states.

Abstract

Grants and funding