Spectral densities of response functions for the O(3) symmetric Anderson and two channel Kondo models

S. Bradley, R. Bulla, A. Hewson () and G Zhang

The European Physical Journal B: Condensed Matter and Complex Systems, 1999, vol. 11, issue 4, 535-550

Abstract: The O(3) symmetric Anderson model is an example of a system which has a stable low energy marginal Fermi liquid fixed point for a certain choice of parameters. It is also exactly equivalent, in the large U limit, to a localized model which describes the spin degrees of freedom of the linear dispersion two channel Kondo model. We first use an argument based on conformal field theory to establish this precise equivalence with the two channel model. We then use the numerical renormalization group (NRG) approach to calculate both one-electron and two-electron response functions for a range of values of the interaction strength U. We compare the behaviours about the marginal Fermi liquid and Fermi liquid fixed points and interpret the results in terms of a renormalized Majorana fermion picture of the elementary excitations. In the marginal Fermi liquid case the spectral densities of all the Majorana fermion modes display a |ω| dependence on the lowest energy scale, and in addition the zero Majorana mode has a delta function contribution. The weight of this delta function is studied as a function of the interaction U and is found to decrease exponentially with U for large U. Using the equivalence with the two channel Kondo model in the large U limit, we deduce the dynamical spin susceptibility of the two channel Kondo model over the full frequency range. We use renormalized perturbation theory to interpret the results and to calculate the coefficient of the lnω divergence found in the low frequency behaviour of the T=0 dynamic susceptibility. Copyright Società Italiana di Fisica, Springer-Verlag 1999

Keywords: PACS. 71.10.Hf Non-Fermi-liquid ground states, electron phase diagrams and phase transitions in model systems, 71.27.+a Strongly correlated electron systems; heavy fermions, (search for similar items in EconPapers)
Date: 1999
References: Add references at CitEc
Citations:

Downloads: (external link)
http://hdl.handle.net/10.1007/s100510051181 (text/html)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:spr:eurphb:v:11:y:1999:i:4:p:535-550:10.1007/s100510051181

Ordering information: This journal article can be ordered from
http://www.springer.com/economics/journal/10051

DOI: 10.1007/s100510051181

Access Statistics for this article

The European Physical Journal B: Condensed Matter and Complex Systems is currently edited by P. Hänggi and Angel Rubio

More articles in The European Physical Journal B: Condensed Matter and Complex Systems from Springer, EDP Sciences
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().