Universal low-temperature crossover in two-channel Kondo models
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.
Cite
@article{arxiv.1203.4456,
title = {Universal low-temperature crossover in two-channel Kondo models},
author = {Andrew K. Mitchell and Eran Sela},
journal= {arXiv preprint arXiv:1203.4456},
year = {2012}
}
Comments
26 pages, 14 figures: updated version including new a section and figure comparing exact results to finite-temperature numerical renormalization group calculations