Fully gapped s-wave superconductivity enhanced by magnetic criticality in heavy fermion system

Abstract

In heavy fermion systems, higher-rank multipole operators are active thanks to the strong spin-orbit interaction (SOI), and the role of diverse multipole fluctuations on the pairing mechanism attracts a lot of attention. Here, we study a mechanism of superconductivity in heavy fermion systems, by focusing on the impact of vertex corrections (VCs) for the pairing interaction going beyond the Migdal approximation. In heavy fermion systems, strong interference between multipole fluctuations cause significant VCs, that represent many-body effects beyond mean-field-type approximations. Especially, the coupling constants between electrons and charged-bosons, including the electron-phonon coupling constant, are strongly magnified by the VCs. For this reason, moderate even-rank (=electric) multipole fluctuations give large attractive interaction, and therefore s-wave superconductivity can emerge in heavy-fermion systems. In particular, phonon-mediated superconductivity is expected to be realized near the magnetic criticality, thanks to the VCs due to magnetic multipole fluctuations. The present mechanism may be responsible for the fully gapped s-wave superconducting state realized in CeCu2Si2.

arXiv comment15 pages, 9 figures, to be published in Physical Review B

References in corpus (34)

• Superconducting phases of f-electron compounds
• Orbital Fluctuation Mediated Superconductivity in Iron Pnictides: Analysis of Five Orbital Hubbard-Holstein Model
• Angular Position of Nodes in the Superconducting Gap of Quasi-2D Heavy-Fermion Superconductor CeCoIn_5
• Signatures of valence fluctuations in CeCu2Si2 under high pressure
• Rotational Symmetry Breaking in the Hidden-Order Phase of URu2Si2
• Theory of Superconductivity in Strongly Correlated Electron Systems
• Kondo Effects and Multipolar Order in the cubic PrTr2Al20 (Tr=Ti, V)
• Modelling the Localized to Itinerant Electronic Transition in the Heavy Fermion System CeIrIn5
• Arrested Kondo effect and hidden order in URu_2Si_2
• Self-Consistent Vertex Correction Analysis for Iron-Based Superconductors: Mechanism of Coulomb-Interaction-Driven Orbital Fluctuations
• Anomalous Transport Phenomena in Fermi Liquids with Strong Magnetic Fluctuations
• Emergent Rank-5 'Nematic' Order in URu2Si2
• Multiband superconductivity with unexpected deficiency of nodal quasiparticles in CeCu2Si2
• Nematicity and magnetism in FeSe and other families of Fe-based superconductors
• Sign-reversing orbital polarization in the nematic phase of FeSe due to the $C_2$ symmetry-breaking in the self-energy
• Fully gapped superconductivity with no sign change in the prototypical heavy-fermion CeCu2Si2
• Fully gapped $d$-wave superconductivity in CeCu${}_2$Si${}_2$
• Evidence for Octupole Order in Ce${}_{0.7}$La${}_{0.3}$B${}_6$ from Resonant X-ray Scattering
• Emergent loop-nodal s${}_{\pm }$-wave superconductivity in CeCu${}_2$Si${}_2$: similarities to the iron-based superconductors
• Spin-triplet superconductivity in Sr2RuO4 due to orbital and spin fluctuations: Analyses by two-dimensional renormalization group theory and self-consistent vertex-correction method
• Spin Triplet Superconductivity in Sr2RuO4 due to Orbital and Spin Fluctuations: Analysis by Two-Dimensional Renormalization Group Theory
• Theoretical prediction and spectroscopic fingerprints of an orbital transition in CeCu2Si2
• Formation Mechanism of Hybridization Gap in Kondo Insulators based on a Realistic Band Model and Application to YbB${}_{12}$
• Meta-orbital Transition in Heavy-fermion Systems: Analysis by Dynamical Mean Field Theory and Self-consistent Renormalization Theory of Orbital Fluctuations
• Calculation of Effective Coulomb Interaction for $P{r}^{3+}$, $U^{4+}$, and $UP{t}_3$
• Nematicity, magnetism and superconductivity in FeSe under pressure: Unified explanation based on the self-consistent vertex correction theory
• Competing d-Wave and p-Wave Spin-Singlet Superconductivities in the Two-Dimensional Kondo Lattice
• Thermodynamic study of gap structure and pair-breaking effect by magnetic field in the heavy-fermion superconductor CeCu2Si2
• Revisit of the Orbital-Fluctuation-Mediated Superconductivity in LiFeAs: Nontrivial Spin-Orbit Interaction Effects on the Bandstructure and Superconducting Gap Function
• Functional renormalization group study of orbital fluctuation mediated superconductivity: Impact of the electron-boson coupling vertex corrections
• High-resolution resonant inelastic soft X-ray scattering as a probe of the crystal electrical field in lanthanides demonstrated for the case of CeRh2Si2
• Superconductivity in the Orbital Degenerate Model for Heavy Fermion Systems
• Vertex corrections in antiferromagnetic spin fluctuation theories
• Plain $s$-wave superconductivity near the magnetic criticality: Enhancement of attractive electron-boson coupling vertex corrections

Cited by in corpus (14)

• Mechanism of exotic density-wave and beyond-Migdal unconventional superconductivity in kagome metal AV3Sb5 (A=K, Rb, Cs)
• Unconventional density waves and superconductivities in Fe-based superconductors and other strongly correlated electron systems
• Unconventional fully-gapped superconductivity in the heavy-fermion metal CeCu${}_2$Si${}_2$
• A Rigorous Formalism of Unconventional Symmetry Breaking in Fermi Liquid Theory and Its Application to Nematicity in FeSe
• Multipole fluctuation theory for heavy fermion systems: Application to multipole orders in CeB6
• Hexadecapole fluctuation mechanism for s-wave heavy fermion superconductor CeCu2Si2: Interplay between intra- and inter-orbital Cooper pairs
• Multipole-fluctuation pairing mechanism of $d_{x^2-y^2}+ig$ superconductivity in Sr${}_2$RuO${}_4$
• High-energy magnetic excitations from heavy quasiparticles in CeCu${}_2$Si${}_2$
• Coupling of optical phonons with Kondo effect and magnetic orders in antiferromagnetic Kondo lattice CeAuSb${}_2$
• $d$- and $p$-wave quantum liquid crystal orders in cuprate superconductors, $\kappa$-(BEDT-TTF)${}_2$X, and coupled chain Hubbard models: functional-renormalization-group analysis
• Doping effects on electronic states in electron-doped FeSe: Impact of self-energy and vertex corrections
• Unified mechanism of charge-density-wave and high-$T_c$ superconductivity protected from oxygen vacancies in bilayer nickelates
• Robust $T$-Linear Resistivity due to SU(4) Valley + Spin Fluctuation Mechanism in Magic Angle Twisted Bilayer Graphene
• Superconductivity and the quasiparticle mass enhancement near the CDW critical point using Bethe-Salpeter method: Application to cuprates