Universal dephasing rate due to diluted Kondo impurities
Abstract
We calculate the dephasing rate due to magnetic impurities in a weakly disordered metal as measured in a weak localization experiment. If the density n_S of magnetic impurities is sufficiently low, the dephasing rate 1/tau_phi is a universal function, 1/tau_phi = (n_S/nu) f(T/T_K), where T_K is the Kondo temperature and nu the density of states. We show that inelastic vertex corrections with a typical energy transfer Delta E are suppressed by powers of 1/(tau_phi Delta E) proportional to n_S. Therefore the dephasing rate can be calculated from the inelastic cross section proportional to pi nu Im T- |pi nu T|^2, where T is the T-matrix which is evaluated numerically exactly using the numerical renormalization group.
Cite
@article{arxiv.cond-mat/0509583,
title = {Universal dephasing rate due to diluted Kondo impurities},
author = {T. Micklitz and A. Altland and T. A. Costi and A. Rosch},
journal= {arXiv preprint arXiv:cond-mat/0509583},
year = {2007}
}
Comments
4 pages, 3 figures; minor modifications, version accepted by PRL