Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 21: Focus Session: Topological Kagome Metals
TT 21.7: Vortrag
Donnerstag, 30. September 2021, 16:00–16:15, H7
Nature of unconventional pairing in the kagome superconductors AV3Sb5 — •Xianxin Wu1, Tilman Schwemmer2, Tobias Müller2, Armando Consiglio2, Giorgio Sangiovanni2, Domenico Di Sante3, Yasir Iqbal4, Werner Hanke2, Andreas P. Schnyder1, M. Michael Denner5, Mark H. Fischer5, Titus Neupert5, and Ronny Thomale2 — 1Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany — 2University of Würzburg, Würzburg, Germany — 3University of Bologna, Bologna, Italy — 4Indian Institute of Technology Madras, Chennai, India — 5University of Zurich, Zurich, Switzerland
The recent discovery of AV3Sb5 (A=K,Rb,Cs) has uncovered an intriguing arena for exotic Fermi surface instabilities in a kagome metal. Among them, superconductivity is found in the vicinity of multiple van Hove singularities, exhibiting indications of unconventional pairing. We show that the sublattice interference mechanism is central to understanding the formation of superconductivity in a kagome metal. Starting from an appropriately chosen minimal tight-binding model with multiple van Hove singularities close to the Fermi level for AV3Sb5, we provide a random phase approximation analysis of superconducting instabilities. Non-local Coulomb repulsion, the sublattice profile of the van Hove bands, and the interaction strength turn out to be the crucial parameters to determine the preferred pairing symmetry. Implications for potentially topological surface states are discussed, along with a proposal for additional measurements to pin down the nature of superconductivity in AV3Sb5.