Nonlinear Response of a Kondo system: Direct and Alternating Tunneling Currents
Abstract
Non - equilibrium tunneling current of an Anderson impurity system subject to both constant and alternating electric fields is studied. A time - dependent Schrieffer - Wolff transformation maps the time - dependent Anderson Hamiltonian onto a Kondo one. Perturbation expansion in powers of the Kondo coupling strength is carried out up to third order, yielding a remarkably simple analytical expression for the tunneling current. It is found that the zero - bias anomaly is suppressed by an ac - field. Both dc and the first harmonic are equally enhanced by the Kondo effect, while the higher harmonics are relatively small. These results are shown to be valid also below the Kondo temperature.
Keywords
Cite
@article{arxiv.cond-mat/9710085,
title = {Nonlinear Response of a Kondo system: Direct and Alternating Tunneling Currents},
author = {Y. Goldin and Y. Avishai},
journal= {arXiv preprint arXiv:cond-mat/9710085},
year = {2009}
}
Comments
7 pages, RevTeX, 3 PS figures attached, the article has been significantly developed: time - dependent Schrieffer - Wolff transformation is presented in the full form, the results are applied to the change in the direct current induced by an alternating field (2 figures are new)