Kondo impurities in the Kitaev spin liquid: Numerical renormalization group solution and gauge-flux-driven screening

Abstract

Kitaev's honeycomb-lattice compass model describes a spin liquid with emergent fractionalized excitations. Here we study the physics of isolated magnetic impurities coupled to the Kitaev spin-liquid host. We reformulate this Kondo-type problem in terms of a many-state quantum impurity coupled to a multichannel bath of Majorana fermions and present the numerically exact solution using Wilson's numerical renormalization group technique. Quantum phase transitions occur as a function of Kondo coupling and locally applied field. At zero field, the impurity moment is partially screened only when it binds an emergent gauge flux, and otherwise becomes free at low temperatures. We show how Majorana degrees of freedom determine the fixed-point properties, make contact with Kondo screening in pseudogap Fermi systems, and discuss effects away from the dilute limit.

arXiv comment5+10 pages, 5+9 figs, (v2) minor modifications, final version as published

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Cited by in corpus (28)

• Physics of the Kitaev model: fractionalization, dynamical correlations, and material connections
• Hunting Majorana Fermions in Kitaev Magnets
• The range of non-Kitaev terms and fractional particles in RuCl${}_3$
• Experimental signatures of quantum and topological states in frustrated magnetism
• Evidence for a spinon Kondo effect in cobalt atoms on single-layer 1T-TaSe${}_2$
• Electrical probes of the non-Abelian spin liquid in Kitaev materials
• Electrical Access to Ising Anyons in Kitaev Spin Liquids
• Kondo screening in a charge-insulating spinon metal
• Spin-glass state and reversed magnetic anisotropy induced by Cr doping in the Kitaev magnet $\alpha$-RuCl${}_3$
• Interlayer Coupling Effect on a Bilayer Kitaev Model
• Scanning tunneling spectroscopy of Majorana zero modes in a Kitaev spin liquid
• Vison-Majorana complex zero-energy resonance in Kitaev's spin liquid
• Dynamical anyon generation in Kitaev honeycomb non-Abelian spin liquids
• Kondo effect in twisted bilayer graphene
• Spin liquid mediated RKKY interaction
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• $Z_2$ flux binding to higher-spin impurities in the Kitaev spin liquid
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• Competition between Kondo and Kitaev Physics in Kitaev clusters coupled to a fermionic bath
• Response and phase transition of a Kitaev spin liquid in a local magnetic field
• Magnetic order through Kondo coupling to quantum spin liquids
• Dilution of the magnetic lattice in the Kitaev candidate $\alpha$-RuCl${}_3$ by Rh${}^{3+}$ doping
• Vacancies in generic Kitaev spin liquids
• Robustness of Vacancy-Bound Non-Abelian Anyons in the Kitaev Model in a Magnetic Field
• Detecting symmetry fractionalization in gapped quantum spin liquids by magnetic impurities
• Realizing Majorana fermion modes in the Kitaev model
• Majorana Signatures in Planar Tunneling through a Kitaev Spin Liquid
• Tunable anyonic permeability across ${\mathbb{Z}}_2$ spin liquid junctions