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arXiv · 1203.4456

Universal low-temperature crossover in two-channel Kondo models

Andrew K. Mitchell·Eran Sela
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Abstract

An exact expression is derived for the electron Green function in two-channel Kondo models with one and two impurities, describing the crossover from non-Fermi liquid (NFL) behavior at intermediate temperatures to standard Fermi liquid (FL) physics at low temperatures. Symmetry-breaking perturbations generically present in experiment ensure the standard low-energy FL description, but the full crossover is wholly characteristic of the unstable NFL state. Distinctive conductance lineshapes in quantum dot devices should result. We exploit a connection between this crossover and one occurring in a classical boundary Ising model to calculate real-space electron densities at finite temperature. The single universal finite-temperature Green function is then extracted by inverting the integral transformation relating these Friedel oscillations to the t matrix. Excellent agreement is demonstrated between exact results and full numerical renormalization group calculations.

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Andrew K. Mitchell, Eran Sela. 2012-05-29. Universal low-temperature crossover in two-channel Kondo models. https://doi.org/10.1103/physrevb.85.235127

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