Superconductivity, Fermi-liquid transport, and universal kinematic scaling relation for metallic thin films with stabilized defect complexes

Abstract

Detailed analysis reveals that an incorporation of stabilized defect complexes within metallic thin films, though a highly disordering and nonequilibrium process, gives rise to superconductivity, Fermi-liquid (FL) transport, and a universal correlation among them. This remarkable manifestation of correlated macroscopic quantum effects is attributed to a phonon-mediated electron-electron, e-e, scattering channel which encompasses both Koshino-Taylor and Bergmann's pseudo-Umklapp processes. This channel---denoted below as pseudo-Umklapp e-e scattering channel---is distinctly different from traditional ones in that disorder leads to a breakdown of lattice momentum conservation (significantly enlarging available phase space), to a spectral weight transfer towards lower frequencies (modifying electron-phonon coupling constant $\ensuremath{\lambda}$), and to a relaxation of kinematic constraints (all phonic polarization modes become available for mediation). On modeling the distorted structure in terms of Hosemann's paracrystal and using standard quantum many-body techniques, we demonstrate the role of distortion and softening in establishing this pseudo-Umklapp channel and, consequently, the surge of superconductivity, the FL transport, and the correlation of their parameters. This unifying approach allows us to derive analytical expressions for ${T}_{c}({\ensuremath{\rho}}_{\ensuremath{\circ}})$ (hallmark of superconductivity), the coefficient $A({\ensuremath{\rho}}_{\ensuremath{\circ}})$ (hallmark of FL transport), and the universal kinematic scaling relation $\mathrm{ln}(\frac{{T}_{c}}{\ensuremath{\theta}})\ensuremath{\propto}{A}^{\frac{\ensuremath{-}1}{2}}$: All are in satisfactory agreement with experiments ($\ensuremath{\theta}$ is an energy scale; residual resistivity ${\ensuremath{\rho}}_{\ensuremath{\circ}}$ measures the extent of disorder).