Prochain séminaire

Séminaire LPMMC

Anton Khvalyuk (LPMMC)
Analytical description of the superfluid stiffness in strongly disordered superconductors
Lieu : G 421
le mercredi 15 février 2023 à 11:00
Personne à contacter : Denis Basko ()

The problem of the temperature dependence of the superfluid stiffness Θ in strongly disordered pseudo-gapped superconductors is relevant for the search of superconducting superinductors – the devices much wanted for several fields of modern quantum technology. The key theoretical challenge is twofold: 1) one has to consistently describe the substantially inhomogeneous superconducting state, known to exist in such superconductors [1,2] even moderately far from the superconductor-insulator transition, and 2) after that one has to calculate the macroscopic electromagnetic response of the resulting disorder media, a challenging problem in its own right. In this talk, we address both of these problems and derive an analytical equation that describes the temperature variation of the superfluid stiffness. At low temperatures, the temperature variation of the superfluid stiffness is close to a power law, Θ(T = 0) - Θ(T) ∝ Tb, where the exponent b ~ 2-3 is disorder-dependent. This result is in qualitative agreement with the experimental results obtained recently by Thibault Charpentier from the Néel Institute.

[1] B. Sacépé, T. Dubouchet, C. Chapelier, M. Sanquer, M. Ovadia, D. Shahar, M.V. Feigel\'man and L.B. Ioffe, "Localization of preformed Cooper pairs in disordered superconductors", Nature Physics 7, 3 (2011), pp. 239–244.
[2] A.V. Khvalyuk and M.V. Feigel\'man, "Distribution of the order parameter in strongly disordered superconductors: An analytic theory", Phys. Rev. B 104 (2021), pp. 224505.