Abstract
In magnetic memory devices, logical bits are recorded by selectively setting the magnetization vector of individual magnetic domains either ‘up’ or ‘down’. In such devices, the fastest and most efficient recording method involves precessional switching1,2,3,4: when a magnetic field Bp is applied as a write pulse over a period τ, the magnetization vector precesses about the field until Bpτ reaches the threshold value at which switching occurs. Increasing the amplitude of the write pulse Bp might therefore substantially shorten the required switching time τ and allow for faster magnetic recording. Here we use very short pulses of a very high magnetic field5 to show that under these extreme conditions, precessional switching in magnetic media supporting high bit densities no longer takes place at well-defined field strengths; instead, switching occurs randomly within a wide range of magnetic fields. We attribute this behaviour to a momentary collapse of the ferromagnetic order of the spins under the load of the short and high-field pulse, thus establishing an ultimate limit to the speed of deterministic switching and magnetic recording.
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References
Gerrits, Th. et al. Ultrafast precessional magnetization reversal by picosecond magnetic field pulse shaping. Nature 418, 509–511 (2002)
Hiebert, W. K., Ballentine, G. E. & Freeman, M. R. Comparison of experimental and numerical micromagnetic dynamics in coherent precessional switching and modal oscillations. Phys. Rev. B 65, 140404(R) (2002)
Kaka, S. & Russek, S. E. Precessional switching of submicrometer spin valves. Appl. Phys. Lett. 86, 2958–2960 (2002)
Schumacher, H. W. et al. Phase coherent precessional magnetization reversal in microscopic spin valve elements. Phys. Rev. Lett. 90, 017201 (2003)
Siegmann, H. C. et al. Magnetism with picosecond field pulses. J. Magn. Magn. Mater. 151, L8–L12 (1995)
Rhie, H.-S., Dürr, H. A. & Eberhardt, W. Femtosecond electron and spin dynamics in Ni/W(110) films. Phys. Rev. Lett. 90, 247201 (2003)
Kiselev, S. I. et al. Microwave oscillations of a nanomagnet driven by a spin-polarized current. Nature 425, 380–383 (2003)
Urazhdin, S. et al. Current-driven magnetic excitations in permalloy-based multilayer nanopillars. Phys. Rev. Lett. 91, 146803 (2003)
Back, C. H. et al. Magnetization reversal in ultrashort magnetic field pulses. Phys. Rev. Lett. 81, 3251–3254 (1998)
Lu, B. et al. High anisotropy CoCrPt(B) media for perpendicular magnetic recording. J. Appl. Phys. 93, 6751–6753 (2003)
Hillebrands, B. & Ounadjela, K. (eds) Spin Dynamics in Confined Magnetic Structures I (Springer, Berlin, 2002)
Weller, D. & Moser, A. Thermal effect limits in ultrahigh-density magnetic recording. IEEE Trans. Magn. 35, 4423–4439 (1999)
Ebels, U., Buda, L. D., Ounadjela, K. & Wigen, P. E. in Spin Dynamics in Confined Magnetic Structures I (eds Hillebrands, B. & Ounadjela, K.) 178–181 (Springer, Berlin, 2002)
Safonov, V. L. & Bertram, H. N. Spin-wave dynamic reversal in a quasi-single domain magnetic grain. Phys. Rev. B 63, 094419 (2001)
Acknowledgements
We thank R. Iverson, C. Field and G. J. Collet for their assistance in preparing and carrying out the sample exposure at FFTB, and A. Vaterlaus for help with imaging the magnetic patterns. This work was carried out at the Stanford Linear Accelerator Center, which is supported by the Office of High Energy and Nuclear Physics of the US Department of Energy (DOE). The experimental programme of the SSRL authors is funded by the Office of Basic Energy Sciences of DOE.
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Supplementary Information
A table summarizes data with a variety of different recording media. Four figures show grain size distribution, magneto-optic patterns, mean switching mode, and mechanism of magnetostatic coupling respectively. (PDF 558 kb)
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Tudosa, I., Stamm, C., Kashuba, A. et al. The ultimate speed of magnetic switching in granular recording media. Nature 428, 831–833 (2004). https://doi.org/10.1038/nature02438
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DOI: https://doi.org/10.1038/nature02438
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