Spin in a Fluctuating Field: The Bose (+Fermi) Kondo models

Simple item page
dc.creatorSengupta, Anirvan M.
dc.date1997-07-30
dc.date.accessioned2026-07-07T09:11:59Z
dc.date.available2026-07-07T09:11:59Z
dc.descriptionI consider models with an impurity spin coupled to a fluctuating gaussian field with or without additional Kondo coupling of the conventional sort. In the case of isotropic fluctuations, the renormalisation group flows for these models have controlled fixed points when the autocorrelation of the gaussian field $h(t)$, $<T h(t) h(0)> \sim {1\over t^{2-ε}}$ with small positive $ε$. In absence of any additional Kondo coupling, I get powerlaw decay of spin correlators, $<T S(t) S(0)> \sim {1\over t^ε}$ . For negative $ε$, the spin autocorrelation is constant in long time limit. The results agree with calculations in Schwinger Boson mean field theory. In presence of a Kondo coupling to itinerant electrons, the model shows a phase transition from a Kondo phase to a field fluctuation dominated phase. These models are good starting points for understanding behaviour of impurities in a system near a zero-temperature magnetic transition. They are also useful for understanding the dynamical local mean field theory of Kondo lattice with Heisenberg (spin-glass type) magnetic interactions.
dc.description4 pages, 2 eps figures (uses epsfig)
dc.identifierhttps://arxiv.org/abs/cond-mat/9707316
dc.identifierhttp://arxiv.org/abs/cond-mat/9707316
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/151874
dc.subjectStrongly Correlated Electrons
dc.titleSpin in a Fluctuating Field: The Bose (+Fermi) Kondo models
dc.typetext

Files

Collections

arXiv