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

Autor: H. Maehara, Alina M. Deac, Shinji Yuasa, Yoshishige Suzuki, Naoki Watanabe, K. Tsunekawa, Yoshinori Nagamine, Akio Fukushima, David D. Djayaprawira, Hitoshi Kubota
Rok vydání: 2008
Předmět:
Zdroj: Nature Physics. 4:803-809
ISSN: 1745-2481
1745-2473
DOI: 10.1038/nphys1036
Popis: 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.
6 figures 1 supplementary information file
Databáze: OpenAIRE
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