We demonstrate the strong impact of the oscillator agility on the line broadening by studying spin transfer induced microwave emission in MgO-based tunnel junctions with current. The linewidth is almost not affected by decreasing the temperature. At very low currents, a strong enhancement of the linewidth at low temperature is attributed to an increase of the non linearity, probably due to the field-like torque. Finally we evidence that the noise is not dominated by thermal fluctuations but rather by the chaotization of the magnetization system induced by the spin transfer torque.
Cite
@article{arxiv.0904.0880,
title = {Origin of the spectral linewidth in non linear oscillators based on MgO tunnel junctions},
author = {B. Georges and J. Grollier and V. Cros and A. Fert and A. Fukushima and H. Kubota and K. Yakushijin and S. Yuasa and K. Ando},
journal= {arXiv preprint arXiv:0904.0880},
year = {2015}
}
Comments
12 pages, 3 figures, published in Phys. Rev. B 80, 060404 (2009)