Andreev reflection through a quantum dot coupled with two ferromagnets and a superconductor
Abstract
We study the Andreev reflection (AR) in a three terminal mesoscopic hybrid system, in which two ferromagnets (F and F) are coupled to a superconductor (S) through a quantum dot (QD). By using non-equilibrium Green function, we derive a general current formula which allows arbitrary spin polarizations, magnetization orientations and bias voltages in F and F. The formula is applied to study both zero bias conductance and finite bias current. The current conducted by crossed AR involving F, F and S is particularly unusual, in which an electron with spin incident from one of the ferromagnets picks up another electron with spin from the other one, both enter S and form a Cooper pair. Several special cases are investigated to reveal the properties of AR in this system.
Keywords
Cite
@article{arxiv.cond-mat/0104103,
title = {Andreev reflection through a quantum dot coupled with two ferromagnets and a superconductor},
author = {Yu Zhu and Qing-feng Sun and Tsung-han Lin},
journal= {arXiv preprint arXiv:cond-mat/0104103},
year = {2009}
}
Comments
15 pages, 7 figures, LaTeX