The influence of spin orbit interaction on phonons and superconductivity in the noncentrosymmetric superconductors LaPt3Si and LaPtSi3. (July 2017)

• Record Type: Journal Article
• Authors: Uzunok, H.Y.; Tütüncü, H.M.; Srivastava, G.P.; Başoǧlu, A.
• Is Part Of: Intermetallics. Volume 86(2017)
• Page Start: 1
• Page End: 10
• Publication Date: 2017-07
• Subjects: Intermetallics -- Density functional theory -- Electronic structure -- Superconducting properties -- ab initio calculations -- Physical properties; Intermetallic compounds -- Metallography -- Periodicals; Metallic glasses -- Periodicals; Composés intermétalliques -- Métallographie -- Périodiques; 669.94
• DOI: 10.1016/j.intermet.2017.03.004
• Languages: English
• ISSNs: 0966-9795

Abstract

Abstract: We have performed ab initio study of structural, electronic, vibrational and electron-phonon interaction properties of LaPt3 Si and LaPtSi3 by employing the density functional theory, a linear-response formalism, and the plane-wave pseudopotential method. The electronic structure, phonon dispersion relations and the Eliashberg spectral function for these materials have been examined with and without the inclusion of spin-orbit interaction (SOI). Our electron-phonon interaction results reveal that the influence of spin-orbit interaction on phonons and superconductivity in these noncentrosymmetric superconductors is very small. Thus, we can conclude that a mixing of the spin-singlet and the spin-triplet components in these superconductors is weak and the spin-singlet Cooper pairs dominate. By integrating the Eliashberg spectral function α 2 F ( ω ), the average electron-phonon coupling parameter λ is obtained to be 0.470 for LaPt3 Si and 0.488 for LaPtSi3, indicating these to be weak-coupling BCS superconductors. Using an acceptable value of μ ∗ = 0.13 for the effective Coulomb repulsion parameter, the superconducting critical temperature T c is calculated to be 0.67 K for LaPt3 Si and 1.39 K for LaPtSi3, in good accordance with experimental values of 0.65 K and 1.52 K, respectively. Graphical abstract: Highlights: Electronic properties of LaPt3 Si and LaPtSi3 are investigated using ab initio pseudopotential method. Phonons and electron-phonon interaction are studied using a linear response theory. The effect of spin-orbit interaction on superconductivity in these materials is very small. λ is found to be 0.4703 for LaPt3 Si and 0.4883 for LaPtSi3 ·K. T c is determined to be 0.67 K for LaPt3 Si and 1.39 K for LaPtSi3 .