Numerical Renormalization Group for Impurity Quantum Phase Transitions: Structure of Critical Fixed Points

dc.creatorLee, Hyun-Jung
dc.creatorBulla, Ralf
dc.creatorVojta, Matthias
dc.date2005-06-27
dc.date.accessioned2026-07-07T06:21:44Z
dc.date.available2026-07-07T06:21:44Z
dc.descriptionThe numerical renormalization group method is used to investigate zero temperature phase transitions in quantum impurity systems, in particular in the particle-hole symmetric soft-gap Anderson model. The model displays two stable phases whose fixed points can be built up of non-interacting single-particle states. In contrast, the quantum phase transitions turn out to be described by interacting fixed points, and their excitations cannot be described in terms of free particles. We show that the structure of the many-body spectrum of these critical fixed points can be understood using renormalized perturbation theory close to certain values of the bath exponents which play the role of critical dimensions. Contact is made with perturbative renormalization group calculations for the soft-gap Anderson and Kondo models. A complete description of the quantum critical many-particle spectra is achieved using suitable marginal operators; technically this can be understood as epsilon-expansion for full many-body spectra.
dc.description14 pages, 12 figures
dc.identifierhttps://arxiv.org/abs/cond-mat/0506694
dc.identifierhttp://arxiv.org/abs/cond-mat/0506694
dc.identifierJ. Phys.: Condens. Matter 17, 6935 (2005)
dc.identifierdoi:10.1088/0953-8984/17/43/012
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/95695
dc.subjectStrongly Correlated Electrons
dc.subjectStatistical Mechanics
dc.titleNumerical Renormalization Group for Impurity Quantum Phase Transitions: Structure of Critical Fixed Points
dc.typetext

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