Planar spin-transfer device with a dynamic polarizer
Abstract
In planar nano-magnetic devices magnetization direction is kept close to a given plane by the large easy-plane magnetic anisotropy, for example by the shape anisotropy in a thin film. In this case magnetization shows effectively in-plane dynamics with only one angle required for its description. Moreover, the motion can become overdamped even for small values of Gilbert damping. We derive the equations of effective in-plane dynamics in the presence of spin-transfer torques. The simplifications achieved in the overdamped regime allow to study systems with several dynamic magnetic pieces (``free layers''). A transition from a spin-transfer device with a static polarizer to a device with two equivalent magnets is observed. When the size difference between the magnets is less than critical, the device does not exhibit switching, but goes directly into the ``windmill'' precession state.
Cite
@article{arxiv.0705.0406,
title = {Planar spin-transfer device with a dynamic polarizer},
author = {Ya. B. Bazaliy and D. Olaosebikan and B. A. Jones},
journal= {arXiv preprint arXiv:0705.0406},
year = {2009}
}