Spin-transfer pulse switching: From the dynamic to the thermally activated regime

• Published in: Applied physics letters Vol. 97; no. 26
• Main Authors: Bedau, D., Liu, H., Sun, J. Z., Katine, J. A., Fullerton, E. E., Mangin, S., Kent, A. D.
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 27.12.2010
• Subjects: Physics
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.3532960

The effect of thermal fluctuations on spin-transfer switching has been studied for a broad range of time scales (subnanoseconds to seconds) in a model system, a uniaxial thin film nanomagnet. The nanomagnet is incorporated into a spin-valve nanopillar, which is subject to spin-polarized current pulses of variable amplitude and duration. Two physical regimes are clearly distinguished: a long pulse duration regime, in which reversal occurs by spin-transfer assisted thermal activation over an energy barrier, and a short-time large pulse amplitude regime, in which the switching probability is determined by the spin-angular momentum in the current pulse.