Magnonics pp 177-187 | Cite as

Nano-Contact Spin-Torque Oscillators as Magnonic Building Blocks

  • Stefano Bonetti
  • Johan Åkerman
Part of the Topics in Applied Physics book series (TAP, volume 125)


We describe the possibility of using nano-contact spin-torque oscillators (NC-STOs) as fundamental magnonic building blocks. NC-STOs can act as spin wave generators, manipulators, and detectors, and can hence realize all the fundamental functions necessary for fully integrated magnonic devices, which can be fabricated using available CMOS compatible large-scale spin-torque device production processes. We show in particular how a 200 nm sized nano-contact located on an out-of-plane magnetized permalloy “free” magnetic layer can generate spin waves at f≈15 GHz that propagate up to 4 μm away from the nano-contact with wavelength λ=200–300 nm, decay length λ r ≈2 μm and group velocities v g ≈3 μm/ns. We propose that the same type of NC-STOs can be used as spin wave manipulators, via control of the local Gilbert damping, and as spin wave detector using the spin torque diode effect.


Spin Wave Magnetic Layer Decay Length Free Layer Perpendicular Magnetic Anisotropy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Support from the Swedish Foundation for Strategic Research (SSF), the Swedish Research Council (VR) and the Knut and Alice Wallenberg Foundation is gratefully acknowledged. Stefano Bonetti is a Postdoctoral Fellow supported by a grant from the Swedish Research Council (VR) and the Knut and Alice Wallenberg Foundation. Johan Åkerman is a Royal Swedish Academy of Sciences Research Fellow supported by a grant from the Knut and Alice Wallenberg Foundation. We thank M. Madami, G. Consolo, S. Tacchi, G. Carlotti, G. Gubbiotti, F.B. Mancoff, V. Tiberkevich, and A. Slavin for useful discussions.


  1. 1.
    V.V. Kruglyak, S.O. Demokritov, D. Grundler, Magnonics. J. Phys. D, Appl. Phys. 43(26), 260301 (2010) CrossRefGoogle Scholar
  2. 2.
    F. Bloch, Zur theorie des ferromagnetismus. Z. Phys. 61(3–4), 206–219 (1930) CrossRefGoogle Scholar
  3. 3.
    S. Neusser, D. Grundler, Magnonics: spin waves on the nanoscale. Adv. Mater. 21, 2927–2932 (2009) CrossRefGoogle Scholar
  4. 4.
    S.A. Nikitov, P. Tailhades, C.S. Tsai, Spin waves in periodic magnetic structures–magnonic crystals. J. Magn. Magn. Mater. 236(3), 320–330 (2001) CrossRefGoogle Scholar
  5. 5.
    Y.K. Fetisov, C.E. Patton, Microwave bistability in a magnetostatic wave interferometer with external feedback. IEEE Trans. Magn. 35(2), 1024–1036 (1999) CrossRefGoogle Scholar
  6. 6.
    S. Tacchi, M. Madami, G. Gubbiotti, G. Carlotti, A.O. Adeyeye, S. Neusser, B. Botters, D. Grundler, Magnetic normal modes in squared antidot array with circular holes: a combined Brillouin light scattering and broadband ferromagnetic resonance study. IEEE Trans. Magn. 46(2), 172–178 (2010) CrossRefGoogle Scholar
  7. 7.
    M.J. Pechan, C. Yu, R.L. Compton, J.P. Park, P.A. Crowell, Direct measurement of spatially localized ferromagnetic-resonance modes in an antidot lattice (invited). J. Appl. Phys. 97(10), 10J903 (2005) CrossRefGoogle Scholar
  8. 8.
    J. Slonczewski, Current-driven excitation of magnetic multilayers. J. Magn. Magn. Mater. 159(1–2), L1–L7 (1996) CrossRefGoogle Scholar
  9. 9.
    L. Berger, Emission of spin waves by a magnetic multilayer traversed by a current. Phys. Rev. B 54(13), 9353–9358 (1996) CrossRefGoogle Scholar
  10. 10.
    M. Tsoi, A.G.M. Jansen, J. Bass, W.-C. Chiang, M. Seck, V. Tsoi, P. Wyder, Excitation of a magnetic multilayer by an electric current. Phys. Rev. Lett. 80(19), 4281–4284 (1998) CrossRefGoogle Scholar
  11. 11.
    M. Tsoi, A.G. Jansen, J. Bass, W.C. Chiang, V. Tsoi, P. Wyder, Generation and detection of phase-coherent current-driven magnons in magnetic multilayers. Nature 406(6791), 46–48 (2000) CrossRefGoogle Scholar
  12. 12.
    W. Rippard, M. Pufall, S. Kaka, S. Russek, T. Silva, Direct-current induced dynamics in Co90Fe10/Ni80Fe20 point contacts. Phys. Rev. Lett. 92(2), 027201 (2004) CrossRefGoogle Scholar
  13. 13.
    S.I. Kiselev, J.C. Sankey, I.N. Krivorotov, N.C. Emley, R.J. Schoelkopf, R.A. Buhrman, D.C. Ralph, Microwave oscillations of a nanomagnet driven by a spin-polarized current. Nature 425(6956), 380–383 (2003) CrossRefGoogle Scholar
  14. 14.
    F.B. Mancoff, N.D. Rizzo, B.N. Engel, S. Tehrani, Phase-locking in double-point-contact spin-transfer devices. Nature 437(7057), 393–395 (2005) CrossRefGoogle Scholar
  15. 15.
    S. Bonetti, Magnetization dynamics in nano-contact spin torque oscillators. Ph.D. thesis, Kungliga Tekniska Högskolan, The Royal Institute of Technology, Stockholm, Sweden (2010) Google Scholar
  16. 16.
    J. Slonczewski, Excitation of spin waves by an electric current. J. Magn. Magn. Mater. 195(2), 261–268 (1999) CrossRefGoogle Scholar
  17. 17.
    W.H. Rippard, M.R. Pufall, T.J. Silva, Quantitative studies of spin-momentum-transfer-induced excitations in co/cu multilayer films using point-contact spectroscopy. Appl. Phys. Lett. 82(8), 1260–1262 (2003) CrossRefGoogle Scholar
  18. 18.
    A. Slavin, V. Tiberkevich, Spin wave mode excited by spin-polarized current in a magnetic nanocontact is a standing self-localized wave bullet. Phys. Rev. Lett. 95(23), 237201 (2005) CrossRefGoogle Scholar
  19. 19.
    D. Berkov, N. Gorn, Magnetization oscillations induced by a spin-polarized current in a point-contact geometry: mode hopping and nonlinear damping effects. Phys. Rev. B 76(14), 144414 (2007) CrossRefGoogle Scholar
  20. 20.
    D. Berkov, J. Miltat, Spin-torque driven magnetization dynamics: micromagnetic modeling. J. Magn. Magn. Mater. 320(7), 1238–1259 (2008) CrossRefGoogle Scholar
  21. 21.
    G. Consolo, B. Azzerboni, L. Lopez-Diaz, G. Gerhart, E. Bankowski, V. Tiberkevich, A. Slavin, Micromagnetic study of the above-threshold generation regime in a spin-torque oscillator based on a magnetic nanocontact magnetized at an arbitrary angle. Phys. Rev. B 78(1), 014420 (2008) CrossRefGoogle Scholar
  22. 22.
    G. Consolo, B. Azzerboni, G. Gerhart, G. Melkov, V. Tiberkevich, A. Slavin, Excitation of self-localized spin-wave bullets by spin-polarized current in in-plane magnetized magnetic nanocontacts: a micromagnetic study. Phys. Rev. B 76(14), 144410 (2007) CrossRefGoogle Scholar
  23. 23.
    W. Rippard, M. Pufall, S. Kaka, T. Silva, S. Russek, Current-driven microwave dynamics in magnetic point contacts as a function of applied field angle. Phys. Rev. B 70(10), 100406(R) (2004) CrossRefGoogle Scholar
  24. 24.
    S. Bonetti, V. Tiberkevich, G. Consolo, G. Finocchio, P. Muduli, F. Mancoff, A. Slavin, J. Åkerman, Experimental evidence of self-localized and propagating spin wave modes in obliquely magnetized current-driven nanocontacts. Phys. Rev. Lett. 105(21), 1–4 (2010) CrossRefGoogle Scholar
  25. 25.
    G. Gerhart, E. Bankowski, G. Melkov, V. Tiberkevich, A. Slavin, Angular dependence of the microwave-generation threshold in a nanoscale spin-torque oscillator. Phys. Rev. B 76(2), 024437 (2007) CrossRefGoogle Scholar
  26. 26.
    V.E. Demidov, S. Urazhdin, S.O. Demokritov, Direct observation and mapping of spin waves emitted by spin-torque nano-oscillators. Nat. Mater. 9(12), 984–988 (2010) CrossRefGoogle Scholar
  27. 27.
    M. Madami, S. Bonetti, G. Consolo, S. Tacchi, G. Carlotti, G. Gubbiotti, F.B. Mancoff, M.A. Yar, J. Åkerman, Direct observation of a propagating spin wave induced by spin-transfer torque. Nat. Nanotechnol. 6, 635–638 (2011) CrossRefGoogle Scholar
  28. 28.
    V.E. Demidov, S.O. Demokritov, B. Hillebrands, M. Laufenberg, P.P. Freitas, Radiation of spin waves by a single micrometer-sized magnetic element. Appl. Phys. Lett. 85(14), 2866–2868 (2004) CrossRefGoogle Scholar
  29. 29.
    T. Neumann, T. Schneider, A.A. Serga, B. Hillebrands, An electro-optic modulator-assisted wavevector-resolving Brillouin light scattering setup. Rev. Sci. Instrum. 80(5), 053905 (2009) CrossRefGoogle Scholar
  30. 30.
    V.E. Demidov, S.O. Demokritov, K. Rott, P. Krzysteczko, G. Reiss, Self-focusing of spin waves in permalloy microstripes. Appl. Phys. Lett. 91(25), 252504 (2007) CrossRefGoogle Scholar
  31. 31.
    S. Bonetti, P. Muduli, F. Mancoff, J. Åkerman, Spin torque oscillator frequency versus magnetic field angle: the prospect of operation beyond 65 GHz. Appl. Phys. Lett. 94(10), 102507 (2009) CrossRefGoogle Scholar
  32. 32.
    M.A. Hoefer, M.J. Ablowitz, B. Ilan, M.R. Pufall, T.J. Silva, Theory of magnetodynamics induced by spin torque in perpendicularly magnetized thin films. Phys. Rev. Lett. 95(26), 267206 (2005) CrossRefGoogle Scholar
  33. 33.
    W.H. Rippard, A.M. Deac, M.R. Pufall, J.M. Shaw, M.W. Keller, S.E. Russek, C. Serpico, Spin-transfer dynamics in spin valves with out-of-plane magnetized CoNi free layers. Phys. Rev. B 81(1), 014426 (2010) CrossRefGoogle Scholar
  34. 34.
    S.M. Mohseni, S.R. Sani, J. Persson, T.N. Anh Nguyen, S. Chung, Y. Pogoryelov, J. Åkerman, High frequency operation of a spin-torque oscillator at low field. Phys. Status Solidi (RRL) – Rapid Res. Lett. 5(12), 432–434 (2011) CrossRefGoogle Scholar
  35. 35.
    S. Mizukami, F. Wu, A. Sakuma, J. Walowski, D. Watanabe, T. Kubota, X. Zhang, H. Naganuma, M. Oogane, Y. Ando, T. Miyazaki, Long-lived ultrafast spin precession in manganese alloys films with a large perpendicular magnetic anisotropy. Phys. Rev. Lett. 106(11), 1–4 (2011) CrossRefGoogle Scholar
  36. 36.
    S. Kaka, M.R. Pufall, W.H. Rippard, T.J. Silva, S.E. Russek, J.A. Katine, Mutual phase-locking of microwave spin torque nano-oscillators. Nature 437(7057), 389–392 (2005) CrossRefGoogle Scholar
  37. 37.
    M. Pufall, W. Rippard, S. Russek, S. Kaka, J. Katine, Electrical measurement of spin-wave interactions of proximate spin transfer nanooscillators. Phys. Rev. Lett. 97(8), 087206 (2006) CrossRefGoogle Scholar
  38. 38.
    P.K. Muduli, Y. Pogoryelov, S. Bonetti, G. Consolo, F. Mancoff, J. Åkerman, Nonlinear frequency and amplitude modulation of a nanocontact-based spin-torque oscillator. Phys. Rev. B 81(14), 140408(R) (2010) CrossRefGoogle Scholar
  39. 39.
    M.R. Pufall, W.H. Rippard, S. Kaka, T.J. Silva, S.E. Russek, Frequency modulation of spin-transfer oscillators. Appl. Phys. Lett. 86(8), 082506 (2005) CrossRefGoogle Scholar
  40. 40.
    P.K. Muduli, Y. Pogoryelov, Y. Zhou, F. Mancoff, Spin torque oscillators and RF currents modulation, locking, and ringing. Integr. Ferroelectr. 125, 37–41 (2011) CrossRefGoogle Scholar
  41. 41.
    P.K. Muduli, Y. Pogoryelov, F. Mancoff, J. Akerman, Modulation of individual and mutually synchronized nanocontact-based spin torque oscillators. IEEE Trans. Magn. 47(6), 1575–1579 (2011) CrossRefGoogle Scholar
  42. 42.
    Y. Pogoryelov, P.K. Muduli, S. Bonetti, E. Iacocca, F. Mancoff, J. Åkerman, Frequency modulation of spin torque oscillator pairs. Appl. Phys. Lett. 98(19), 192501 (2011) CrossRefGoogle Scholar
  43. 43.
    Y. Pogoryelov, P.K. Muduli, S. Bonetti, F. Mancoff, J. Åkerman, Spin-torque oscillator linewidth narrowing under current modulation. Appl. Phys. Lett. 98(19), 192506 (2011) CrossRefGoogle Scholar
  44. 44.
    F.B. Mancoff, N.D. Rizzo, B.N. Engel, S. Tehrani, Area dependence of high-frequency spin-transfer resonance in giant magnetoresistance contacts up to 300 nm diameter. Appl. Phys. Lett. 88(11), 112507 (2006) CrossRefGoogle Scholar
  45. 45.
    M.P. Kostylev, A.A. Serga, T. Schneider, T. Neumann, B. Leven, B. Hillebrands, R.L. Stamps, Resonant and nonresonant scattering of dipole-dominated spin waves from a region of inhomogeneous magnetic field in a ferromagnetic film. Phys. Rev. B 76, 184419 (2007) CrossRefGoogle Scholar
  46. 46.
    V. Tiberkevich, A. Slavin, J.-V. Kim, Microwave power generated by a spin-torque oscillator in the presence of noise. Appl. Phys. Lett. 91(19), 192506 (2007) CrossRefGoogle Scholar
  47. 47.
    F. Maci, A.D. Kent, F.C. Hoppensteadt, Spin-wave interference patterns created by spin-torque nano-oscillators for memory and computation. Nanotechnology 22, 095301 (2011) CrossRefGoogle Scholar
  48. 48.
    A.A. Tulapurkar, Y. Suzuki, A. Fukushima, H. Kubota, H. Maehara, K. Tsunekawa, D.D. Djayaprawira, N. Watanabe, S. Yuasa, Spin-torque diode effect in magnetic tunnel junctions. Nature 438(7066), 339–342 (2005) CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.School of Information and Communication Technology, Materials PhysicsKTH – Royal Institute of TechnologyKista-StockholmSweden
  2. 2.Department of PhysicsUniversity of GothenburgGothenburgSweden
  3. 3.Stanford Institute for Materials and Energy Science (SIMES)Stanford UniversityStanfordUSA

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