Magnetic disorder in superconductors: Enhancement by mesoscopic fluctuations

QUEST Center event
No
Speaker
I. S. Burmistrov (Landau Institute)
Date
04/05/2017 - 16:30 - 15:30Add to Calendar 2017-05-04 15:30:00 2017-05-04 16:30:00 Magnetic disorder in superconductors: Enhancement by mesoscopic fluctuations We study the density of states (DOS) and the transition temperature Tc 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 for mesoscopic fluctuations of the local DOS, and, consequently, for the effective strength of magnetic impurities. We find that these mesoscopic fluctuations result in a non-zero 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 Tc by spin-flip scattering can be faster or slower than in the standard mean-field theory. Nanotechnology building (206) - 9th floor Department of Physics physics.dept@mail.biu.ac.il Asia/Jerusalem public
Place
Nanotechnology building (206) - 9th floor
Abstract

We study the density of states (DOS) and the transition temperature Tc 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 for mesoscopic fluctuations of the local DOS, and, consequently, for the effective strength of magnetic impurities. We find that these mesoscopic fluctuations result in a non-zero 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 Tc by spin-flip scattering can be faster or slower than in the standard mean-field theory.

Last Updated Date : 01/05/2017