We discuss a mesoscopic mechanism of exchange interaction in ferromagnet-normal metal-ferromagnet multilayers. We show that in the case when the metal's thickness is larger than the electron mean free path, the relative orientation of magnetizations in the ferromagnets is perpendicular. The exchange energy between ferromagnets decays with the metal thickness as a power law.
@article{arxiv.cond-mat/9909064,
title = {Mesoscopic mechanism of exchange interaction in magnetic multilayers},
author = {A. Zyuzin and B. Spivak and I. Vagner and P. Wyder},
journal= {arXiv preprint arXiv:cond-mat/9909064},
year = {2009}
}