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

Nature Physics volume 4, pages 803809 (2008) | Download Citation

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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, so far, the development of industrially attractive prototypes has been hampered by the inability to identify systems that 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, although showing 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 structure.

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Acknowledgements

The authors thank J. C. Slonczewski, G. E. W. Bauer, T. J. Silva, S. E. Russek, M. Mizuguchi, R. Jansen and J. M. Shaw for discussions. This research was partially supported by SCOPE-MIC and MEXT. A.M.D. acknowledges support from the Japan Society for the Promotion of Science through the research grant P05330.

Author information

Affiliations

  1. Osaka University, Graduate School of Engineering Science, Department of Materials Engineering Science, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan

    • Alina M. Deac
    • , Hiroki Maehara
    •  & Yoshishige Suzuki
  2. National Institute of Advanced Industrial Science and Technology (AIST), Nanoelectronics Research Institute, 1-1-1 Umezono, Tsukuba 305-8568, Japan

    • Alina M. Deac
    • , Akio Fukushima
    • , Hitoshi Kubota
    • , Hiroki Maehara
    • , Yoshishige Suzuki
    •  & Shinji Yuasa
  3. Canon ANELVA Corporation, Electron Device Division, 5-1-2 Kurigi, Asao, Kawasaki 215-8550, Japan

    • Hiroki Maehara
    • , Yoshinori Nagamine
    • , Koji Tsunekawa
    • , David D. Djayaprawira
    •  & Naoki Watanabe

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Contributions

A.M.D. carried out the measurements, analysed the data and wrote the paper. A.F. and H.K. developed the patterning process and fabricated the samples. A.F. also provided considerable help with the experimental set-up. H.K., Y.N., K.T., D.D.D. and N.W. optimized the sputtering process for low-RA MgO magnetic tunnel junctions and deposited the multilayers. S.Y. helped develop the magnetic tunnel junction and carried out studies for increasing the TMR. Y.S. helped with analysing the data and calculated the losses in the system. All authors discussed the result and commented on the manuscript.

Corresponding author

Correspondence to Alina M. Deac.

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    Supplementary Information, Supplementary Figures 1—8 and Supplementary Table 1

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DOI

https://doi.org/10.1038/nphys1036

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