arXiv 0803.28712008-03-19cond-mat.othercond-mat.mtrl-sci

Strong linewidth variation for spin-torque nano-oscillators as a function of in-plane magnetic field angle

K. V. Thadani, G. Finocchio, Z. -P. Li, O. Ozatay, J. C. Sankey, I. N. Krivorotov, Y. -T. Cui, R. A. Buhrman, D. C. Ralph

备注：: 15 pages, 5 figures
发表信息：: Phys. Rev. B 78, 024409 (2008)
DOI：: 10.1103/PhysRevB.78.024409

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We measure the microwave signals produced by spin-torque-driven magnetization dynamics in patterned magnetic multilayer devices at room temperature, as a function of the angle of a magnetic field applied in the sample plane. We find strong variations in the frequency linewidth of the signals, with a decrease by more than a factor of 20 as the field is rotated from the magnetic easy axis to the in-plane hard axis. Based on micromagnetic simulations, we identify these variations as due to a transition from spatially incoherent to coherent precession.

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