1. Conventional superconductivity in the doped kagome superconductor Cs(V0.86Ta0.14)3Sb5 from vortex lattice studies.
- Author
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Xie, Yaofeng, Chalus, Nathan, Wang, Zhiwei, Yao, Weiliang, Liu, Jinjin, Yao, Yugui, White, Jonathan S., DeBeer-Schmitt, Lisa M., Yin, Jia-Xin, Dai, Pengcheng, and Eskildsen, Morten Ring
- Subjects
IRON-based superconductors ,SMALL-angle neutron scattering ,CHARGE density waves ,DEGREES of freedom ,SUPERCONDUCTIVITY - Abstract
A hallmark of unconventional superconductors is a complex electronic phase diagram where intertwined orders of charge-spin-lattice degrees of freedom compete and coexist. While the kagome metals such as CsV
3 Sb5 also exhibit complex behavior, involving coexisting charge density wave order and superconductivity, much is unclear about the microscopic origin of the superconducting pairing. We study the vortex lattice in the superconducting state of Cs(V0.86 Ta0.14 )3 Sb5 , where the Ta-doping suppresses charge order and enhances superconductivity. Using small-angle neutron scattering, a strictly bulk probe, we show that the vortex lattice exhibits a strikingly conventional behavior. This includes a triangular symmetry with a period consistent with 2e-pairing, a field dependent scattering intensity that follows a London model, and a temperature dependence consistent with a uniform superconducting gap. Our results suggest that optimal bulk superconductivity in Cs(V1−x Tax )3 Sb5 arises from a conventional Bardeen-Cooper-Schrieffer electron-lattice coupling, different from spin fluctuation mediated unconventional copper- and iron-based superconductors. The mechanism of superconductivity in layered kagome metals remains unclear, however its coexistence with charge order suggests exotic interpretations. Here the authors study the vortex lattice in the superconducting state of Ta-doped CsV3 Sb5 with suppressed charge order, suggesting conventional pairing. [ABSTRACT FROM AUTHOR]- Published
- 2024
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