2024/11/22 by Keshri, Sonu Prasad, Guang‐Yu Guo, Guo, Guang-Yu
Engineering · Physics and Astronomy · #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Superconducting Materials and Applications #Superconductivity (cond-mat.supr-con) #Superconductivity in MgB2 and Alloys
paper · pdf · doi:10.48550/arxiv.2411.14734
openalex publication_date 2024/11/22 · openalex created_date 2024/12/04 · openalex updated_date 2026/07/28
We investigate the superconducting (SC) properties of experimentally realised γ-BiPd by solving the anisotropic Migdal-Eliashberg equations in conjunction with \it ab initio relativistic calculations of the electron and phonon band structures as well as electron-phonon coupling (EPC) matrix elements. Our study reveals that γ-BiPd possesses a complex Fermi surface (FS), consisting of two electron pockets and one hole pocket, each characterised by distinct atomic orbitals. Our key finding is that the superconductivity in γ-BiPd is primarily orbital-selective, arising from Bi p-orbitals, and distributed anisotropically on the FS, although contribution from Pd d-orbitals, particularly on the hole pocket, is also discernable. While our results show an anisotropic nature of the \bf k-dependent SC gap Δ\bf k and EPC strength λ\bf k across the FS, calculated superconducting quasiparticle density of states NS spectra exhibit a U-shaped gap and Δ\bf k distribution forms a single peak, being consistent with the spin-singlet s-wave superconductivity observed in this material. The calculated Tc is ∼2.0 K, agreeing in order of magnitude with the experimental value of 3.3 K in γ-BiPd thin films. The predicted EPC-enhanced Sommerfeld coefficient γn of 0.141 mJ/K2cm3 is similar to the experimental γn value (0.119 mJ/K2cm3) of the isoelectronic and isostructural Bi(Pd0.5Pt0.5) alloy.