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Séminaire Théorie : jeudi 13 juillet 2023 à 11h00

Mikhail Feigelman (LPMMC, Grenoble)

Titre : Theory of the 1st order superconductor-insulator transition

 Lien zoom : https://univ-grenoble-alpes-fr.zoom.us/j/99884767935?pwd=dmpSVGVFZ2I5WkQyNEFLN2t1dVhEQT09

Meeting ID : 998 8476 7935 – Passcode: 630179
LPMMC, Salle G421

Résumé : Recent experimental studies of transport in strongly disordered Indium Oxide films revealed an unusual first-order phase transition between superconducting and insulating state, with the jump of kinetic inductance of the system at the transition. In the present work we propose interpretation of this transition as the transition between superconducting state built on top of Cooper pairs localized due to disorder present in the system, and a Coulomb-glass type insulator with developed Coulomb gap. To describe this transition analytically, we present a theoretical model formulated in terms of Anderson pseudospins. Utilizing mean-field Parisi replica-symmetry breaking scheme, we demonstrate the existence of a region in the parameter space where both phases are locally stable w.r.t. small fluctuations, which is the necessary condition for the first order phase transition. Finally, we provide estimates on the free energy of both phases and the position of the transition itself. The talk will start from an extensive exposition of the SIT subject, which has a long history.