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Journal of Physics Condensed Matter

Phonon effects on a multichannel resonance-level model

Qingshan Yuan, Hong Chen, Yumei Zhang, Yuguang Chen, Xiang Xia Wu

Published Sep 1, 1997• 0 citations
Publisher

Abstract

The phonon effects on a multichannel resonant-level model have been studied by a bosonization technique and canonical transformations. We found that the model can be mapped onto a single-channel Kondo model and the non-Fermi-liquid transition is modified by local electron - phonon interaction. At strong interaction, only one channel of conducting electrons is necessary in order to realize this transition and it is the phonon effects that control the behaviour of the system.

DOI
10.1088/0953-8984/9/35/012

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The phonon effects on a multichannel resonant-level model have been studied by a bosonization technique and canonical transformations. We found that the model can be mapped onto a single-channel Kondo model and the non-Fermi-liquid transition is modified by local electron - phonon interaction. At strong interaction, only one channel of conducting electrons is necessary in order to realize this transition and it is the phonon effects that control the behaviour of the system.
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We analyze the structure of the perturbation expansion of the general multichannel Kondo model with channel anisotropic exchange couplings and in the presence of an external magnetic field, generalizing to this case the Anderson-Yuval technique. For two channels, we are able to map the Kondo model onto a generalized resonant-level model. Limiting cases in which the equivalent resonant-level model is solvable are identified. The solution correctly captures the properties of the two-channel Kondo model, and also allows an analytic description of the crossover from the non-Fermi-liquid to the Fermi-liquid behavior caused by the channel anisotropy.
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