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Superfluid Stiffness of Systems with Bogoliubov Fermi Surfaces

ORAL

Abstract

Bogoliubov Fermi surfaces are topologically protected regions of zero energy excitations in a superconductor whose dimension equals that of the underlying normal state Fermi surface. Hamiltonians exhibiting this "ultranodal" phase are regarded as unphysical if superfluid stiffness is negative. In this work we show that superfluid stiffness is positive within large areas of the parameter space of our previously proposed model Hamiltonian, confirming that the proposed model has stable ultranodal phase. We further investigate the the free energy expansion beyond Gaussian levell, and investigate the possibility that the instability in the case of negative stiffness can be to pair density wave order.

Presenters

  • Yifu Cao

    Department of Physics, University of Florida

Authors

  • Yifu Cao

    Department of Physics, University of Florida

  • Chandan Setty

    Physics and Astronomy, Rice university, Department of Physics, University of Florida, Physics, University of Florida

  • Andreas Kreisel

    Universität Leipzig, Institute for Theoretical Physics, University of Leipzig, Institute for Theoretical Physics, Leipzig University, Institut für Theoretische Physik, Universität Leipzig, University of Leipzig

  • Shinibali Bhattacharyya

    University of Florida, Department of Physics, University of Florida

  • Peter Hirschfeld

    University of Florida, Department of Physics, University of Florida, Physics, University of Florida, univ of Florida