Accueil > Agenda Scientifique

19 novembre 2020: 1 événement

séminaire

  • Superconductivity from Coulomb repulsion in Luttinger semimetals

    Jeudi 19 novembre 11:00-12:00 - Sergueï Tchoumakov, Institut Néel - Institut Néel

    Superconductivity from Coulomb repulsion in Luttinger semimetals

    Résumé : The Coulomb repulsion between electrons is sometimes believed to act against the formation of Cooper pairs and thus the observation of superconductivity. I will explain how the electron screening of the Coulomb potential can actually lead to superconductivity, based on the Kohn-Luttinger and plasmon mechanisms. We proceed to quantitatively evaluate which part of the dielectric function affects the critical temperature the most.
    Since superconductivity from the Coulomb repulsion performs better at smaller doping, we explore how interband coupling affects superconductivity by studying the Coulomb mechanism for Luttinger semimetals. The dielectric function is then affected by virtual transitions between bands, which we explore in detail and compute the resulting superconducting critical temperature. Finally we review experimental observations to see where this mechanism of superconductivity may occur.
    [1] S. Tchoumakov and W. Witczak-Krempa, Phys.Rev.B 100, 075104 (2019)
    [2] S. Tchoumakov, L.J. Godbout and W. Witczak-Krempa, Phys. Rev. Research 2, 013230 (2020).
    [3] L.J. Godbout, S. Tchoumakov and W. Witczak-Krempa, Phys. Rev. B 102, 205202 (2020).

    Lieu : ONLINE

    En savoir plus : Superconductivity from Coulomb repulsion in Luttinger semimetals