Dynamical 1/N approach to time-dependent currents through quantum dots
Abstract
A systematic truncation of the many-body Hilbert space is implemented to study how electrons in a quantum dot attached to conducting leads respond to time-dependent biases. The method, which we call the dynamical 1/N approach, is first tested in the most unfavorable case, the case of spinless fermions (N=1). We recover the expected behavior, including transient ringing of the current in response to an abrupt change of bias. We then apply the approach to the physical case of spinning electrons, N=2, in the Kondo regime for the case of infinite intradot Coulomb repulsion. In agreement with previous calculations based on the non-crossing approximation (NCA), we find current oscillations associated with transitions between Kondo resonances situated at the Fermi levels of each lead. We show that this behavior persists for a more realistic model of semiconducting quantum dots in which the Coulomb repulsion is finite.
Cite
@article{arxiv.cond-mat/0305080,
title = {Dynamical 1/N approach to time-dependent currents through quantum dots},
author = {J. Merino and J. B. Marston},
journal= {arXiv preprint arXiv:cond-mat/0305080},
year = {2009}
}
Comments
18 pages, 7 eps figures, discussion extended for spinless electrons and typos