Interorbital singlet pairing in Sr2RuO4: A Hund's superconductor
Journal article, 2022
We study the superconducting gap function of Sr2RuO4. By solving the linearized Eliashberg equation with a correlated pairing vertex extracted from a dynamical mean-field calculation we identify the dominant pairing channels. An analysis of the candidate gap functions in orbital and quasiparticle band basis reveals that an interorbital singlet pairing of even parity is in agreement with experimental observations. It reconciles in particular the occurrence of a two-component order parameter with the presence of line nodes of quasiparticles along the c axis in the superconducting phase. The strong angular dependence of the gap along the Fermi surface is in stark contrast to its quasilocality when expressed in the orbital basis. We identify local interorbital spin correlations as the driving force for the pairing and thus reveal the continuation of Hund's physics into the superconducting phase.
Author
Stefan Käser
Max Planck Society
University of Erlangen-Nuremberg (FAU)
Hugo Strand
Örebro University
Flatiron Institute
Chalmers, Physics
Nils Wentzell
Flatiron Institute
A. Georges
École polytechnique
University of Geneva
Collège de France
Flatiron Institute
Olivier Parcollet
University Paris-Saclay
Flatiron Institute
Philipp Hansmann
Max Planck Society
University of Erlangen-Nuremberg (FAU)
Physical Review B
2469-9950 (ISSN) 2469-9969 (eISSN)
Vol. 105 15 155101Subject Categories (SSIF 2011)
Condensed Matter Physics
DOI
10.1103/PhysRevB.105.155101