Diffusive superconductors beyond Usadel approximation: Electron-hole asymmetry and large photoelectric effect

Abstract

We extend the quasiclassical formalism for diffusive superconductors by deriving anisotropic (gradient) corrections to the Usadel equation. We demonstrate that in a number of physical situations such corrections may play a crucial role being responsible for the effects which cannot be recovered within the standard Usadel approximation. One of them is the so-called photoelectric effect in superconductors and superconducting-normal (SN) hybrid structures. Provided a superconducting part of the system is irradiated by an external ac electromagnetic field the charge imbalance develops and a non-vanishing dc voltage is induced across the SN interface. In the presence of magnetic impurities in a superconductor the magnitude of this effect becomes large and can easily be detected in modern experiments.

8 pages, 2 figures

References in corpus (4)

• Theory of a large thermoeffect in superconductors doped with magnetic impurities
• Electron-hole imbalance and large thermoelectric effect in superconducting hybrids with spin-active interfaces
• Enhancement of thermoelectric effect in diffusive superconducting bilayers with magnetic interfaces
• Giant thermopower in superconducting heterostructures with spin-active interfaces