Bardasis-Schrieffer-like phase mode in a superconducting bilayer

Abstract

We theoretically study the low-lying collective modes of an even-parity spin-singlet superconducting bilayer, where strong spin-orbit coupling leads to a closely competing odd-parity pairing state. We develop a gauge-invariant theory for the coupling of phase fluctuations to an external electromagnetic field and show that the competing odd-parity pairing instability gives rise to a Bardasis-Schrieffer-like phase mode within the excitation gap. Accounting for the long-range Coulomb interaction, however, we find that this mode is converted into an antisymmetric plasmon and is likely pushed into the quasiparticle continuum.

References in corpus (5)

• Unconventional superconductivity in bilayer transition metal dichalcogenides
• Anomalous Upper Critical Field in CeCoIn_5/YbCoIn_5 Superlattices with a Rashba-type Heavy Fermion Interface
• Odd-parity superconductivity in bilayer transition metal dichalcogenides
• Probing the pairing interaction and multiple Bardasis-Schrieffer modes using Raman spectroscopy
• Violation of the Pauli-Clogston limit in a heavy Fermion superconductor CeRh${}_2$As${}_2$ --Duality of itinerant and localized 4f electrons--

Cited by in corpus (4)

• Light-induced switching between singlet and triplet superconducting states
• Field-induced superconductivity mediated by odd-parity multipole fluctuation
• Superconducting meron phase in locally noncentrosymmetric superconductors
• Collective modes in superconductors including Coulomb repulsion