We propose a device that can operate as a magneto-resistive switch or oscillator. The device is based on a spin-thermo-electronic control of the exchange coupling of two strong ferromagnets through a weakly ferromagnetic spacer. We show that the local Joule heating due to a high concentration of current in a magnetic point contact or a nanopillar can be used to reversibly drive the weak ferromagnet through its Curie point and thereby exchange-decouple the strongly ferromagnetic layers, which have an antiparallel ground state. Such a spin-thermionic parallel-to-antiparallel switching causes magnetoresistance oscillations where the frequency can be controlled by proper biasing from essentially DC to GHz.
@article{arxiv.0710.5477,
title = {Thermoelectrical manipulation of nano-magnets},
author = {A. M. Kadigrobov and R. I. Shekhter and M. Jonson and V. Korenivski},
journal= {arXiv preprint arXiv:0710.5477},
year = {2009}
}