Abstract
We study the density of states (DOS) and the transition temperature in a dirty superconducting film with rare classical magnetic impurities of an arbitrary strength described by the Poissonian statistics. We take into account that the potential disorder is a source of mesoscopic fluctuations of the local DOS, and, consequently, of the effective strength of magnetic impurities. We find that these mesoscopic fluctuations result in a nonzero DOS for all energies in the region of the phase diagram where without this effect the DOS is zero within the standard mean-field theory. This mechanism can be more efficient in filling the mean-field superconducting gap than rare fluctuations of the potential disorder (instantons). Depending on the magnetic impurity strength, the suppression of by spin-flip scattering can be faster or slower than in the standard mean-field theory.
- Received 7 March 2017
- Revised 29 December 2017
DOI:https://doi.org/10.1103/PhysRevB.97.014515
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