Physical properties and electronic structure of the two-gap superconductor V\(_{2}\)Ga\(_{5}\)

• Published in: arXiv.org 2024-05
• Main Authors: P -Y Cheng, Oudah, Mohamed, T -L Hung, C -E Hsu, C -C Chang, J -Y Haung, T -C Liu, C -M Cheng, M -N Ou, W -T Chen, Deng, L Z, C -C Lee, Y -Y Chen, C -N Kuo, C -S Lue, Machts, Janna, Kojima, Kenji M, Hallas, Alannah M, C -L Huang
• Format: Article
• Language: English
• Subjects: Absolute zero; Critical field (superconductivity); Electrical resistivity; Electronic structure; Fermi surfaces; First principles; Muon spin relaxation; Photoelectric emission; Physical properties; Single crystals; Specific heat; Spectrum analysis; Superconductivity
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2405.03499

We present a thorough investigation of the physical properties and superconductivity of the binary intermetallic V2Ga5. Electrical resistivity and specific heat measurements show that V2Ga5 enters its superconducting state below Tsc = 3.5 K, with a critical field of Hc2,perp c(Hc2,para c) = 6.5(4.1) kOe. With H perp c, the peak effect was observed in resistivity measurements, indicating the ultrahigh quality of the single crystal studied. The resistivity measurements under high pressure reveal that the Tsc is suppressed linearly with pressure and reaches absolute zero around 20 GPa. Specific heat and muon spin relaxation measurements both indicate that the two-gap s-wave model best describes the superconductivity of V2Ga5. The spectra obtained from angle-resolved photoemission spectroscopy measurements suggest that two superconducting gaps open at the Fermi surface around the Z and {\Gamma} points. These results are verified by first-principles band structure calculations. We therefore conclude that V2Ga5 is a phonon-mediated two-gap s-wave superconductor