Bias-driven large power microwave emission from MgO-based tunnel magnetoresistance devices

Alina M. Deac; Akio Fukushima; Hitoshi Kubota; Hiroki Maehara; Yoshishige Suzuki; Shinji Yuasa; Yoshinori Nagamine; Koji Tsunekawa; David D. Djayaprawira; Naoki Watanabe

doi:10.1038/nphys1036

arXiv · 0803.2013

Bias-driven large power microwave emission from MgO-based tunnel magnetoresistance devices

Alina M. Deac·Akio Fukushima·Hitoshi Kubota·Hiroki Maehara·Yoshishige Suzuki·Shinji Yuasa·Yoshinori Nagamine·Koji Tsunekawa·David D. Djayaprawira·Naoki Watanabe

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Abstract

Spin-momentum transfer between a spin-polarized current and a ferromagnetic layer can induce steady-state magnetization precession, and has recently been proposed as a working principle for ubiquitous radio-frequency devices for radar and telecommunication applications. However, to-date, the development of industrially attractive prototypes has been hampered by the inability to identify systems which can provide enough power. Here, we demonstrate that microwave signals with device-compatible output power levels can be generated from a single magnetic tunnel junction with a lateral size of 100 nm, seven orders of magnitude smaller than conventional radio-frequency oscillators. We find that in MgO magnetic tunnel junctions the perpendicular torque induced by the spin-polarized current on the local magnetization can reach 25% of the in-plane spin-torque term, while exhibiting a different bias-dependence. Both findings contrast with the results obtained on all-metallic structures - previously investigated -, reflecting the fundamentally different transport mechanisms in the two types of structures.

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Alina M. Deac, Akio Fukushima, Hitoshi Kubota, Hiroki Maehara, Yoshishige Suzuki, Shinji Yuasa, Yoshinori Nagamine, Koji Tsunekawa, David D. Djayaprawira, Naoki Watanabe. 2008-03-18. Bias-driven large power microwave emission from MgO-based tunnel magnetoresistance devices. https://doi.org/10.1038/nphys1036

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