Combining multiple ultrafast spin torque impulses with a 5 nanosecond duration pulse for damping reduction, we observe time-domain precession which evolves from an initial 1 ns duration transient with changing precessional amplitude to constant amplitude oscillations persisting for over 2 ns. These results are consistent with relaxation of the transient trajectories to a stable orbit with nearly zero damping. We find that in order to observe complete damping cancellation and the transient behavior in a time domain sampling measurement, a short duration, fast rise-time pulse is required to cancel damping without significant trajectory dephasing.
@article{arxiv.0908.0481,
title = {Time domain detection of pulsed spin torque damping reduction},
author = {Longfei Ye and Samir Garzon and Richard A. Webb and Mark Covington and Shehzaad Kaka and Thomas M. Crawford},
journal= {arXiv preprint arXiv:0908.0481},
year = {2009}
}
Comments
and suggestions are greatly appreciated (sgarzon at physics dot sc dot edu) 3.5 pages, 3 figures