Nodeless superconductivity and its evolution with pressure in the layered dirac semimetal 2M-WS2
| Autor: | F. von Rohr, Marta Brzezińska, Ekaterina Pomjakushina, Rustem Khasanov, H. Luetkens, M. Z. Hasan, Titus Neupert, Zurab Guguchia, Anthony A. Amato, Joel A. T. Verezhak, Stepan S. Tsirkin, Dariusz Jakub Gawryluk |
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| Přispěvatelé: | University of Zurich, Guguchia, Zurab |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
10120 Department of Chemistry
3104 Condensed Matter Physics 530 Physics FOS: Physical sciences 10192 Physics Institute 02 engineering and technology Electron lcsh:Atomic physics. Constitution and properties of matter 7. Clean energy 01 natural sciences Superconductivity (cond-mat.supr-con) Superfluidity 0103 physical sciences lcsh:TA401-492 010306 general physics Phase diagram Physics Superconductivity Condensed Matter - Materials Science Condensed matter physics Condensed Matter - Superconductivity 2504 Electronic Optical and Magnetic Materials Materials Science (cond-mat.mtrl-sci) Muon spin spectroscopy 021001 nanoscience & nanotechnology Condensed Matter Physics Semimetal Electronic Optical and Magnetic Materials lcsh:QC170-197 Density functional theory lcsh:Materials of engineering and construction. Mechanics of materials 0210 nano-technology Ambient pressure |
| Zdroj: | npj Quantum Materials, Vol 4, Iss 1, Pp 1-8 (2019) npj Quantum Materials |
| ISSN: | 2397-4648 |
| Popis: | The interaction between superconductivity and band topology can lead to various unconventional superconducting (SC) states, and represents a new frontier in condensed matter physics research. Recently, the transition metal dichalcogenide (TMD) system 2M-WS2 has been identified as a Dirac semimetal exhibiting both superconductivity with the highest Tc = 8.5 K among all the TMD materials and topological surface states with a single Dirac cone. Here we report on muon spin rotation (muSR) and density functional theory studies of microscopic SC properties and the electronic structure in 2M-WS2 at ambient and under hydrostatic pressures (p_max = 1.9 GPa). The SC order parameter in 2M-WS2 is determined to have single-gap s-wave symmetry. We further show a strong negative pressure effect on Tc and on the SC gap. This may be partly caused by the pressure induced reduction of the size of the electron pocket around the Gamma-point, at which a band inversion appears up to the highest applied pressure. We also find that the superfluid density ns is very weakly affected by pressure. The absence of a strong pressure effect on the superfluid density and the absence of a correlation between ns and Tc in 2M-WS2, in contrast to the other SC TMDs Td-MoTe2 and 2H-NbSe2, is explained in terms of its location in the optimal (ambient pressure) and above the optimal (under pressure) superconducting regions of the phase diagram and its large distance to the other possible competing or cooperating orders. These results hint towards a complex nature of the superconductivity in TMDs, despite the observed s-wave order parameter. 9 pages, 5 Figures, Supplementary Information, containing the XRD and magnetization data, is available upon request |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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