2002/04/30 by Lijun Zhu, Qimiao Si · 10 citations
Physics and Astronomy · #Boson #Condensed matter physics #Critical exponent #Electron #Kondo effect #Kondo model #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum critical point #Quantum mechanics #Quantum phase transition #Rare-earth and actinide compounds #Spin (aerodynamics) #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.66.024426
published as Phys. Rev. B 66, 024426 (2002) · 15 pages, 13 figures; published version
openalex publication_date 2002/07/19 · arxiv created 2002/09/02 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We consider the critical properties of the Bose-Fermi Kondo model, which describes a local moment simultaneously coupled to a conduction electron band and a fluctuating magnetic field, i.e., a dissipative bath of vector bosons. We carry out an \ensuremathε expansion to higher than linear orders. (Here \ensuremathε is defined in terms of the power-law exponent of the bosonic-bath spectral function.) An unstable fixed point is identified not only in the spin-isotropic case but also in the presence of anisotropy. It marks the point where the weight of the Kondo resonance has just gone to zero, and the local moment fluctuations are critical. The exponent for the local spin susceptibility at this critical point is found to be equal to \ensuremathε in all cases. Our results imply that a quantum phase transition of the ``locally critical'' type is a robust microscopic solution to Kondo lattices.