Critical properties of the Fermi-Bose Kondo and pseudogap Kondo models: Renormalized perturbation theory

Abstract

Magnetic impurities coupled to both fermionic and bosonic baths or to a fermionic bath with pseudogap density of states, described by the Fermi-Bose Kondo and pseudogap Kondo models, display non-trivial intermediate coupling fixed points associated with critical local-moment fluctuations and local non-Fermi liquid behavior. Based on renormalization group together with a renormalized perturbation expansion around the free-impurity limit, we calculate various impurity properties in the vicinity of those intermediate-coupling fixed points. In particular, we compute the conduction electron T matrix, the impurity susceptibility, and the residual impurity entropy, and relate our findings to certain scenarios of local quantum criticality in strongly correlated lattice models.

16 pages, 5 figs; (v2) large-N results for entropy of Bose-Kondo model added; (v3) final version as published

References in corpus (4)

• Quantum phase transitions in the Bose-Fermi Kondo model
• Quantum impurity in an antiferromagnet: non-linear sigma model theory
• The pseudogap Fermi-Bose Kondo model
• Quantum impurity in a magnetic environment

Cited by in corpus (5)

• Phase transitions in the pseudogap Anderson and Kondo models: Critical dimensions, renormalization group, and local-moment criticality
• Quantum critical properties of the Bose-Fermi Kondo Model in a large-N limit
• Dynamical Mean-Field Theory - from Quantum Impurity Physics to Lattice Problems
• Numerical Renormalization Group for Impurity Quantum Phase Transitions: Structure of Critical Fixed Points
• Critical theories for the pseudogap Kondo problem