Condensed Matter Seminar: Michael Smith, University of Notre Dame


Location: 184 Nieuwland Science Hall (View on map )

The Debye Mechanism of Dissipation in Superconductor

Dr. Michael Smith
Postdoctoral Research Associate
University of Notre Dame

The linear ac conductivity in superconductors has been studied extensively, and the conventional theory of Mattis and Bardeen says that the dissipative conductivity at low temperatures is controlled by quasiparticle scattering off of impurities, and thus the linear conductivity is controlled by the elastic quasiparticle relaxation time. I will talk about a new contribution to the linear ac conductivity in superconductors that is proportional to the inelastic quasiparticle relaxation time, which is typically much longer than the elastic relaxation time, and thus this new contribution can be much larger than the conventional contribution. The mechanism that gives rise to this new contribution is similar to the Debye mechanism of microwave absorption in molecular gasses, and can arise in conventional superconductors under the application of a dc supercurrent, in the flux flow regime of type-II superconductors, and in non-centrosymmetric superconductors in the presence of an in-plane magnetic field.

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