The pairing symmetry in quasi-one-dimensional superconductor $\mathrm{Rb_2 Mo_3 As_3}$

Gosar, Žiga (author), Arh, Tina (author), Jaksetič, Kevin (author), Zorko, Andrej (author), Liu, Wenhao (author), Wu, Hanlin (author), Wang, Chennan (author), Luetkens, Hubertus (author), Lv, Bing (author), Arčon, Denis (author)

Quasi-one-dimensional electron systems display intrinsic instability towards long-range ordered phases at sufficiently low temperatures. The superconducting orders are of particular interest as they can possess either singlet or triplet pairing symmetry and frequently compete with magnetism. Here we report on muon spin rotation and relaxation ($\mu$SR) study of Rb$_2$Mo$_3$As$_3$ characterised by one of the highest critical temperatures $T_{\rm c}$ = 10.4 K among quasi-one-dimensional superconductors. The transverse-field $\mu$SR signal shows enhanced damping below $T_{\rm c}$ due to the formation of vortex lattice. Comparison of vortex lattice broadening against single gap $s$−, $p$− and $d$−wave models shows the best agreement for the $s$−wave scenario but with the anomalously small superconducting gap, $\Delta_0$, to $T_{\rm c}$ ratio of 2$\Delta_0∕k_{\rm B} T_{\rm c}$ = 2.74(1). The alternative nodal $p$−wave or $d$−wave scenarios with marginally worse goodness of fit would yield more realistic 2$\Delta_0∕k_{\rm B} T_{\rm c}$ = 3.50(2) and 2$\Delta_0∕k_{\rm B} T_{\rm c}$ = 4.08(1), respectively, and thus they cannot be ruled out when accounting for the superconducting state in Rb$_2$Mo$_3$As$_3$.

• Language: English
• Keywords: solid state physics, superconductivity, unconventional superconductivity, muon spin relaxation, pnictides
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 5 str.
• Numbering: Vol. 181, art. 111478
• PID: 20.500.12556/RUL-148645
• UDC: 538.9
• ISSN on article: 0022-3697
• DOI: 10.1016/j.jpcs.2023.111478
• COBISS.SI-ID: 155028739
• Publication date in RUL: 28.08.2023

Record is a part of a journal

• Title: The journal of physics and chemistry of solids
• Shortened title: J. phys. chem. solids
• Publisher: Elsevier
• ISSN: 0022-3697
• COBISS.SI-ID: 25778944

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: fizika trdne snovi, superprevodnost