Abstract

Topological superconductors (TSCs) are unconventional superconductors with bulk superconducting gap and in-gap Majorana states on the boundary that may be used as topological qubits for quantum computation. Despite their importance in both fundamental research and applications, natural TSCs are very rare. Here, combining state of the art synchrotron and laser-based angle-resolved photoemission spectroscopy, we investigated a stoichiometric transition metal dichalcogenide (TMD), 2M-WS2 with a superconducting transition temperature of 8.8 K (the highest among all TMDs in the natural form up to date) and observed distinctive topological surface states (TSSs). Furthermore, in the superconducting state, we found that the TSSs acquired a nodeless superconducting gap with similar magnitude as that of the bulk states. These discoveries not only evidence 2M-WS2 as an intrinsic TSC without the need of sensitive composition tuning or sophisticated heterostructures fabrication, but also provide an ideal platform for device applications thanks to its van der Waals layered structure.

Topological superconductors are potentially important for future quantum computation, but they are very rare in nature. Here, the authors observe topological surface states acquiring a nodeless superconducting gap with similar magnitude as that of the bulk states in 2M-WS2, suggesting an intrinsic topological superconductor.

Details

Title
Observation of topological superconductivity in a stoichiometric transition metal dichalcogenide 2M-WS2
Author
Li, Y W 1 ; Zheng, H J 2 ; Fang, Y Q 3 ; Zhang, D Q 4 ; Chen, Y J 5 ; Chen, C 6 ; Liang, A J 7 ; Shi, W J 8   VIAFID ORCID Logo  ; Pei, D 9 ; Xu, L X 10 ; Liu, S 10 ; Pan, J 11 ; Lu, D H 12   VIAFID ORCID Logo  ; Hashimoto, M 12   VIAFID ORCID Logo  ; Barinov, A 13   VIAFID ORCID Logo  ; Jung, S W 14   VIAFID ORCID Logo  ; Cacho, C 15   VIAFID ORCID Logo  ; Wang, M X 7 ; He Y 16 ; Fu L 17 ; Zhang, H J 18   VIAFID ORCID Logo  ; Huang, F Q 3   VIAFID ORCID Logo  ; Yang, L X 19 ; Liu, Z K 7   VIAFID ORCID Logo  ; Chen, Y L 20 

1  School of Physical Science and Technology, ShanghaiTech University, Shanghai, People’s Republic of China (GRID:grid.440637.2) (ISNI:0000 0004 4657 8879); University of Oxford, Department of Physics, Oxford, UK (GRID:grid.4991.5) (ISNI:0000 0004 1936 8948); ShanghaiTech Laboratory for Topological Physics, Shanghai, People’s Republic of China (GRID:grid.4991.5) 
2  School of Physical Science and Technology, ShanghaiTech University, Shanghai, People’s Republic of China (GRID:grid.440637.2) (ISNI:0000 0004 4657 8879); ShanghaiTech Laboratory for Topological Physics, Shanghai, People’s Republic of China (GRID:grid.440637.2); University of Chinese Academy of Sciences, Beijing, People’s Republic of China (GRID:grid.410726.6) (ISNI:0000 0004 1797 8419) 
3  State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Science, Shanghai, People’s Republic of China (GRID:grid.454856.e) (ISNI:0000 0001 1957 6294); Peking University, State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering, Beijing, People’s Republic of China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) 
4  China Jiliang University, School of Physics, Hangzhou, People’s Republic of China (GRID:grid.411485.d) (ISNI:0000 0004 1755 1108); National Laboratory of Solid State Microstructures and School of Physics Nanjing University, Nanjing, People’s Republic of China (GRID:grid.41156.37) (ISNI:0000 0001 2314 964X); Collaborative Innovation Center of Advanced Microstructures, Nanjing, People’s Republic of China (GRID:grid.509497.6) 
5  Tsinghua University, State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Beijing, People’s Republic of China (GRID:grid.12527.33) (ISNI:0000 0001 0662 3178) 
6  School of Physical Science and Technology, ShanghaiTech University, Shanghai, People’s Republic of China (GRID:grid.440637.2) (ISNI:0000 0004 4657 8879); ShanghaiTech Laboratory for Topological Physics, Shanghai, People’s Republic of China (GRID:grid.440637.2); Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, USA (GRID:grid.184769.5) (ISNI:0000 0001 2231 4551) 
7  School of Physical Science and Technology, ShanghaiTech University, Shanghai, People’s Republic of China (GRID:grid.440637.2) (ISNI:0000 0004 4657 8879); ShanghaiTech Laboratory for Topological Physics, Shanghai, People’s Republic of China (GRID:grid.440637.2) 
8  ShanghaiTech University, Center for Transformative Science, Shanghai, People’s Republic of China (GRID:grid.440637.2) (ISNI:0000 0004 4657 8879); Shanghai high repetition rate XFEL and extreme light facility (SHINE), ShanghaiTech University, Shanghai, People’s Republic of China (GRID:grid.440637.2) (ISNI:0000 0004 4657 8879) 
9  University of Oxford, Department of Physics, Oxford, UK (GRID:grid.4991.5) (ISNI:0000 0004 1936 8948) 
10  School of Physical Science and Technology, ShanghaiTech University, Shanghai, People’s Republic of China (GRID:grid.440637.2) (ISNI:0000 0004 4657 8879); University of Chinese Academy of Sciences, Beijing, People’s Republic of China (GRID:grid.410726.6) (ISNI:0000 0004 1797 8419) 
11  State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Science, Shanghai, People’s Republic of China (GRID:grid.454856.e) (ISNI:0000 0001 1957 6294) 
12  SLAC National Accelerator Laboratory, Stanford Synchrotron Radiation Lightsource, Menlo Park, USA (GRID:grid.445003.6) (ISNI:0000 0001 0725 7771) 
13  Elettra-Sincrotrone Trieste, Trieste, Basovizza, Italy (GRID:grid.5942.a) (ISNI:0000 0004 1759 508X) 
14  Diamond Light Source, Harwell Campus, Didcot, UK (GRID:grid.18785.33) (ISNI:0000 0004 1764 0696); Gyeongsang National University, Department of Physics, Jinju, Korea (GRID:grid.256681.e) (ISNI:0000 0001 0661 1492) 
15  Diamond Light Source, Harwell Campus, Didcot, UK (GRID:grid.18785.33) (ISNI:0000 0004 1764 0696) 
16  University of California at Berkeley, Department of Physics, Berkeley, USA (GRID:grid.47840.3f) (ISNI:0000 0001 2181 7878) 
17  Massachusetts Institute of Technology, Department of Physics, Cambridge, USA (GRID:grid.116068.8) (ISNI:0000 0001 2341 2786) 
18  National Laboratory of Solid State Microstructures and School of Physics Nanjing University, Nanjing, People’s Republic of China (GRID:grid.41156.37) (ISNI:0000 0001 2314 964X); Collaborative Innovation Center of Advanced Microstructures, Nanjing, People’s Republic of China (GRID:grid.509497.6) 
19  Tsinghua University, State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Beijing, People’s Republic of China (GRID:grid.12527.33) (ISNI:0000 0001 0662 3178); Frontier Science Center for Quantum Information, Beijing, People’s Republic of China (GRID:grid.12527.33) 
20  School of Physical Science and Technology, ShanghaiTech University, Shanghai, People’s Republic of China (GRID:grid.440637.2) (ISNI:0000 0004 4657 8879); University of Oxford, Department of Physics, Oxford, UK (GRID:grid.4991.5) (ISNI:0000 0004 1936 8948); ShanghaiTech Laboratory for Topological Physics, Shanghai, People’s Republic of China (GRID:grid.4991.5); Tsinghua University, State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Beijing, People’s Republic of China (GRID:grid.12527.33) (ISNI:0000 0001 0662 3178) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41467-021-23076-1
ProQuest document ID
2528309545
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.