Overscreened Kondo effect, (color) superconductivity and Shiba states in Dirac metals and quark matter

Abstract

We study the interplay between the Kondo effect and (color) superconductivity in doped Dirac metals with magnetic impurities and in quark matter with colorful impurities. We first point out that the overscreened Kondo effect arises in the normal state of these systems. Next the (color) superconducting gap is incorporated as a mean field and the phase diagram for a varying gap and temperature is constructed nonperturbatively. A rich phase structure emerges from a competition of effects unique to a multichannel system. The Kondo-screened phase is shown to disappear for a sufficiently large gap. Peculiarity of quark matter due to the confining property of non-Abelian gauge fields is noted. We also investigate the spectrum of sub-gap excited states, called Shiba states. Based on a model calculation and physical reasoning we predict that, as the coupling of the impurity to the bulk is increased, there will be more than one quantum phase transition due to level crossing among overscreened states.

25 pages, 15 figures. v2: Figure 9 added, minor revisions. matches published version

References in corpus (16)

• The numerical renormalization group method for quantum impurity systems
• Color superconductivity in dense quark matter
• Dirac materials
• Observation of the two-channel Kondo effect
• Superconductivity of doped Weyl semimetals: finite-momentum pairing and electronic analogues of the 3He-A phase
• BEC-BCS Crossover in the Nambu--Jona-Lasinio Model of QCD
• Phase transitions in the pseudogap Anderson and Kondo models: Critical dimensions, renormalization group, and local-moment criticality
• The Physics of Kondo Impurities in Graphene
• Chiral Lagrangian and spectral sum rules for dense two-color QCD
• Kondo effect and non-Fermi liquid behavior in Dirac and Weyl semimetals
• Single Impurity In Ultracold Fermi Superfluids
• Bound states of a localized magnetic impurity in a superfluid of paired ultracold fermions
• Anderson impurity in a semiconductor
• Strong vs. Weak Coupling Duality and Coupling Dependence of the Kondo Temperature in the Two-Channel Kondo Model
• Quantum phase transition in a gapped Anderson model: A numerical renormalization group study
• Classical spins in topological insulators

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• Heavy-quark spin polarization induced by the Kondo effect in a magnetic field
• Spatial anisotropy of Kondo screening cloud in a type-II Weyl semimetal
• Dirac Kondo effect under magnetic catalysis
• QCD Kondo effect for single heavy quark in chiral-symmetry broken phase
• Competing color superconductivity and color Kondo effect in quark matter
• Yu-Shiba-Rusinov states in color superconducting quark matter