Observation of topological superconductivity in a stoichiometric transition metal dichalcogenide 2M-WS2

• Published in: Nature communications Vol. 12; no. 1; pp. 2874 - 7
• Main Authors: Li, Y. W., Zheng, H. J., Fang, Y. Q., Zhang, D. Q., Chen, Y. J., Chen, C., Liang, A. J., Shi, W. J., Pei, D., Xu, L. X., Liu, S., Pan, J., Lu, D. H., Hashimoto, M., Barinov, A., Jung, S. W., Cacho, C., Wang, M. X., He, Y., Fu, L., Zhang, H. J., Huang, F. Q., Yang, L. X., Liu, Z. K., Chen, Y. L.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.05.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 140/125; 140/146; 147/138; 639/766/119/1003; 639/766/119/2792/4128; Chalcogenides; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Fabrication; Heterostructures; Humanities and Social Sciences; Laboratories; Laser applications; Lasers; Microscopy; multidisciplinary; Photoelectric emission; Physics; Quantum computing; Qubits (quantum computing); Science; Science (multidisciplinary); Spectroscopy; Superconductivity; Synchrotrons; Topography; Topological superconductors; Transition metal compounds; Transition temperature; Transition temperatures; Tungsten disulfide; Unconventional superconductors
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-23076-1

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-WS 2 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-WS 2 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-WS 2 , suggesting an intrinsic topological superconductor.