Physical properties and electronic structure of the two-gap superconductor V₂Ga₅

Abstract: We conducted an in-depth study of the physical properties and superconductivity of the binary intermetallic compound V₂Ga₅. Electrical resistivity and specific heat measurements demonstrate that V₂Ga₅ transitions into its superconducting state below a critical temperature Tsc of 3.5 K, with upper critical fields H_c2,⊥c and H_c2,||c of 6.5 kOe and 4.1 kOe, respectively. A peak effect in resistivity was observed for H_⊥c, highlighting the exceptional quality of the single crystal. High-pressure resistivity measurements show that T_sc decreases linearly with pressure, vanishing around 20 GPa. The two-gap s-wave model best fits the superconducting behavior observed in specific heat measurements. Bands near the Fermi level at the Z and Г points were identified through angle-resolved photoemission spectroscopy and supported by first-principles calculations. These results confirm that V₂Ga₅ is a phonon-mediated two-gap s-wave superconductor.