Current-induced magnetic excitations in Co/Cu/Co bilayer nanopillars (∼50 nm in diameter) have been studied experimentally at low temperatures for large applied fields perpendicular to the layers. At sufficiently high current densities excitations, which lead to a decrease in differential resistance, are observed for both current polarities. Such bipolar excitations are not expected in a single domain model of spin-transfer. We propose that at high current densities strong asymmetries in the longitudinal spin accumulation cause spin-wave instabilities transverse to the current direction in bilayer samples, similar to those we have reported for single magnetic layer junctions.
@article{arxiv.cond-mat/0407210,
title = {Bipolar High Field Excitations in Co/Cu/Co Nanopillars},
author = {B. Özyilmaz and A. D. Kent and M. J. Rooks and J. Z. Sun},
journal= {arXiv preprint arXiv:cond-mat/0407210},
year = {2016}
}
Comments
4 pages, 4 figures+ 2 additional jpg figures (Fig. 2d and Fig. 3) high resolution figures and recent related articles are available at: http://www.physics.nyu.edu/kentlab/news.html