Stability of Bogoliubov Fermi surfaces within BCS theory

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It has recently been realized that the gap nodes of multiband superconductors that break time-reversal symmetry generically take the form of Fermi surfaces of Bogoliubov quasiparticles. However, these Fermi surfaces lead to a nonzero density of states (DOS) at the Fermi energy, which typically disfavors such superconducting states. It has thus not been clear whether they can be stable for reasonable pairing interactions or are in practice preempted by time-reversal-symmetric states with vanishing DOS. In this Letter, we show within BCS theory applied to a paradigmatic model that the time-reversal-symmetry-breaking states are indeed stabilized over broad parameter ranges at weak coupling. Moreover, we introduce a fast method that involves solving the inverse BCS gap equation, does not require iteration, does not suffer from convergence problems, and can handle metastable solutions.


Original languageEnglish
Article numberL220501
Pages (from-to)1-6
Number of pages6
JournalPhysical Review B
Issue number22
Publication statusPublished - 5 Jun 2023

External IDs

Scopus 85163306289


Research priority areas of TU Dresden

DFG Classification of Subject Areas according to Review Boards

Subject groups, research areas, subject areas according to Destatis

ASJC Scopus subject areas


  • Supraleitung, Bogoliubov-Fermi-Flächen, BCS-Theorie, superconductivity, Bogoliubov Fermi surface, BCS theory