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arXiv · 1203.6300

Decoherence and mode-hopping in a magnetic tunnel junction-based spin-torque oscillator

P. K. Muduli·O. G. Heinonen·J. Åkerman
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Abstract

We discuss the coherence of magnetic oscillations in a magnetic tunnel junction-based spin-torque oscillator as a function of external field angle. Time-frequency analysis shows mode-hopping between distinct oscillator modes, which arises from linear and nonlinear couplings in the Landau-Lifshitz-Gilbert equation, analogous to mode-hopping observed in semiconductor ring lasers. These couplings and therefore mode-hopping are minimized near the current threshold for antiparallel (AP) alignment of free layer with reference layer magnetization. Away from the AP alignment, mode-hopping limits oscillator coherence.

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P. K. Muduli, O. G. Heinonen, J. Åkerman. 2012-03-28. Decoherence and mode-hopping in a magnetic tunnel junction-based spin-torque oscillator. https://doi.org/10.1103/physrevlett.108.207203

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