Quantum phase transitions in the Bose-Fermi Kondo model

2002/04/30 by Gergely Zaránd, Gergely Zarand, Eugene Demler · 8 citations
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.66.024427

published as Phys. Rev. B 66, 024427 (2002) · 13 pages, 9 figures, some references added/corrected

arxiv created 2002/05/01 · openalex publication_date 2002/07/19 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We study quantum phase transitions in the Bose-Fermi Kondo problem, where a local spin is coupled to independent bosonic and fermionic degrees of freedom. Applying a second-order expansion in the anomalous dimension of the Bose field, we analyze the various nontrivial fixed points of this model. We show that anisotropy in the couplings is relevant at the SU(2)-invariant non-Fermi-liquid fixed points studied earlier, and thus the quantum phase transition is usually governed by XY or Ising-type fixed points. We furthermore derive an exact result that relates the anomalous exponent of the Bose field to that of the susceptibility at any finite coupling fixed point. Implications for the dynamical mean-field approach to locally quantum critical phase transitions are also discussed.

Citations

• Spin Orthogonality Catastrophe in Two-Dimensional Antiferromagnets and Superconductors

Cited by

• Ultraviolet/infrared mixing-driven suppression of Kondo screening in the antiferromagnetic quantum critical metal
• Quantum impurity in an antiferromagnet: Nonlinear sigma model theory
• Kondo physics and dissipation: A numerical renormalization-group approach to Bose-Fermi Kondo models
• Double-Dot Charge Qubit and Transport via Dissipative Cotunneling
• Dynamical mean-field theory: from quantum impurity physics to lattice problems
• Consequences of the local spin self-energy approximation on the heavy-fermion quantum phase transition
• Quantum impurity models of noisy qubits
• Continuous Quantum Phase Transition in a Kondo Lattice Model

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