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The beta function of the multichannel Kondo model

Kurt Fischer
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Abstract

The beta function of the multichannel Kondo model is calculated exactly in the limit of large spin N and channel number M=gamma*N, with constant gamma. There are no corrections in any finite order of 1/N. One zero is found at a finite coupling strength, showing directly the Non--Fermi liquid behavior of the model. This renormalization group flow allows to introduce a variational principle for the entropy, to obtain the low temperature thermodynamics. Such in particular the low temperature thermodynamics of the non--crossing approximation to the Kondo model becomes accessible.

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Kurt Fischer. 1998-11-17. The beta function of the multichannel Kondo model. https://doi.org/10.1103/physrevb.59.14845

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