A fractional-spin phase in the power-law Kondo model

Abstract

We consider a Kondo impurity coupled to a fermionic host with a power-law density of states near the Fermi level, rho(epsilon) ~ |epsilon|^r, with exponent r<0. Using both perturbative renormalization group (poor man's scaling) and numerical renormalization group methods, we analyze the phase diagram of this model for ferromagnetic and antiferromagnetic Kondo coupling. Both sectors display non-trivial behavior with several stable phases separated by second-order transitions. In particular, on the ferromagnetic side there is a stable intermediate-coupling fixed point with universal properties corresponding to a fractional ground-state spin.

5 pages, 4 figs; (v2) extended discussion and added refs; final version as published

Cited by in corpus (18)

• The numerical renormalization group method for quantum impurity systems
• The Physics of Kondo Impurities in Graphene
• Properties of anisotropic magnetic impurities on surfaces
• The Kondo effect in the presence of the Rashba spin-orbit interaction
• Kondo effect with diverging hybridization: possible realization in graphene with vacancies
• Van Hove singularities in the paramagnetic phase of the Hubbard model: a DMFT study
• Kondo-Anderson Transitions
• Quantum phase transitions and thermodynamics of the power-law Kondo model
• Numerical renormalization group calculation of impurity internal energy and specific heat of quantum impurity models
• Phase boundaries of the pseudogap Anderson and Kondo models
• Spin-anisotropic magnetic impurity in a Fermi gas: poor man's scaling equation integration
• Critical points and non-Fermi liquids in the underscreened pseudogap Kondo model
• Mean-field quantum phase transition in graphene and in general gapless systems
• Poor man's scaling: $XYZ$ Coqblin--Schrieffer model revisited
• Fractional Local Moment and High Temperature Kondo Effect in Rashba-Fermi Gases
• Quantum impurity with 2/3 local moment in 1D quantum wires: an NRG study
• Impurity Quantum Phase Transition in a Current-Carrying d-Wave Superconductor
• Dissipation- versus Chaos-Induced Relaxation in Non-Markovian Quantum Many-Body Systems