Superconductivity suppression in disordered films: Interplay of two-dimensional diffusion and three-dimensional ballistics

Abstract

Suppression of the critical temperature in homogeneously disordered superconducting films is a consequence of the disorder-induced enhancement of Coulomb repulsion. We demonstrate that for the majority of thin films studied now this effect cannot be completely explained in the assumption of two-dimensional diffusive nature of electrons motion. The main contribution to the $T_c$ suppression arises from the correction to the electron-electron interaction constant coming from small scales of the order of the Fermi wavelength that leads to the critical temperature shift $\delta T_c/T_{c0}\sim -1/k_{F}l$, where $k_F$ is the Fermi momentum and $l$ is the mean free path. Thus almost for all superconducting films that follow the fermionic scenario of $T_c$ suppression with decreasing the film thickness, this effect is caused by the proximity to the three-dimensional Anderson localization threshold and is controlled by the parameter $k_{F}l$ rather than the sheet resistance of the film.

arXiv comment13 pages, 9 figures

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Cited by in corpus (5)

• Evidence of the disorder-independent electron-phonon scattering time in thin NbN films
• Interplay of superconductivity and localization near a 2D ferromagnetic quantum critical point
• Robustness of flat band superconductivity against disorder in a two-dimensional Lieb lattice model
• Supercurrent flow in inhomogeneous superconductors
• Inverted pendulum driven by a horizontal random force: statistics of the never-falling trajectory and supersymmetry