Dynamic switching of the spin circulation in tapered magnetic nanodisks

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Magnetic vortices are characterized by the sense of in-plane magnetization circulation and by the polarity of the vortex core. With each having two possible states, there are four possible stable magnetization configurations that can be utilized for a multibit memory cell. Dynamic control of vortex core polarity has been demonstrated using both alternating and pulsed magnetic fields and currents. Here, we show controlled dynamic switching of spin circulation in vortices using nanosecond field pulses by imaging the process with full-field soft X-ray transmission microscopy. The dynamic reversal process is controlled by far-from-equilibrium gyrotropic precession of the vortex core, and the reversal is achieved at significantly reduced field amplitudes when compared with static switching. We further show that both the field pulse amplitude and duration required for efficient circulation reversal can be controlled by appropriate selection of the disk geometry.

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Figure 1: Sample configuration.
Figure 2: MTXM images showing the switching of spin circulation in magnetic vortices by static magnetic fields and field pulses.
Figure 3: Conditions for static and dynamic annihilation of the vortex core.
Figure 4: Temporal evolution of dynamic annihilation of the vortex core.

Change history

  • 24 April 2013

    In the version of this Article originally published online, in the ninth paragraph, the word 'redundant' should not have appeared in the sentence"...are summarized in Table 1 and the minimum pulse durations are plotted in Fig. 3b (blue triangles) for 20-nm-thick disks". In the tenth paragraph, the formula s = RχB/(μ0MS) should have appeared as shown here. These errors have been corrected in all versions of the Article.


  1. 1

    Hubert, A. & Schäfer, R. Magnetic Domains: The Analysis of Magnetic Nanostructures (Springer, 1998).

  2. 2

    Shinjo, T., Okuno, T., Hassdorf, R., Shigeto, K. & Ono, T. Magnetic vortex core observation in circular dots of permalloy. Science 289, 930–932 (2000).

  3. 3

    Wachowiak, A. et al. Direct observation of internal spin structure of magnetic vortex cores. Science 298, 577–580 (2002).

  4. 4

    Choe, S-B. et al. Vortex core-driven magnetization dynamics. Science 304, 420–422 (2004).

  5. 5

    Guslienko, K. Y. et al. Eigenfrequencies of vortex state excitations in magnetic submicron-size disks. J. Appl. Phys. 91, 8037–8039 (2002).

  6. 6

    Novosad, V. et al. Spin excitations of magnetic vortices in ferromagnetic nanodots. Phys. Rev. B 66, 052407 (2002).

  7. 7

    Park, J. P. & Crowell, P. A. Interactions of spin waves with a magnetic vortex. Phys. Rev. Lett. 95, 167201 (2005).

  8. 8

    Buchanan, K. S., Grimsditch, M., Fradin, F. Y., Bader, S. D. & Novosad, V. Driven dynamic mode splitting of the magnetic vortex translational resonance. Phys. Rev. Lett. 99, 267201 (2007).

  9. 9

    Antos, R. & Otani, Y. Simulations of the dynamic switching of vortex chirality in magnetic nanodisks by a uniform field pulse. Phys Rev. B 80, 140404(R) (2009).

  10. 10

    Ishida, T., Kimura, T. & Otani, Y. Current-induced vortex displacement and annihilation in a single permalloy disk. Phys. Rev. B 74, 014424 (2006).

  11. 11

    Pribiag, V. S. et al. Magnetic vortex oscillator driven by d.c. spin-polarized current. Nature Phys. 3, 498–503 (2007).

  12. 12

    Ruotolo, A. et al. Phase-locking of magnetic vortices mediated by antivortices. Nature Nanotech. 4, 528–532 (2009).

  13. 13

    Kosevich, A. M., Ivanov, B. A. & Kovalev, A. S. Magnetic solitons. Phys. Rep. 194, 117–238 (1990).

  14. 14

    Van Waeyenberge, B. et al. Magnetic vortex core reversal by excitation with short bursts of an alternating field. Nature 444, 461–464 (2006).

  15. 15

    Lee, K-S. & Kim, S-K. Two circular-rotational eigenmodes and their giant resonance asymmetry in vortex gyrotropic motions in soft magnetic nanodots. Phys Rev. B 78, 014405 (2008).

  16. 16

    Yamada, K. et al. Electrical switching of the vortex core in a magnetic disk. Nature Mater. 6, 269–273 (2007).

  17. 17

    Bohlens, S. et al. Current controlled random-access memory based on magnetic vortex handedness. Appl. Phys. Lett. 93, 142508 (2008).

  18. 18

    Nakano, K. et al. All-electrical operation of magnetic vortex core memory cell. Appl. Phys. Lett. 99, 262505 (2011).

  19. 19

    Goto, M. et al. Electric spectroscopy of vortex states and dynamics in magnetic disks. Phys. Rev. B 84, 064406 (2011).

  20. 20

    Kikuchi, N. et al. Vertical bistable switching of spin vortex in a circular magnetic dot. J. Appl. Phys. 90, 6548–6549 (2001).

  21. 21

    Hertel, R., Gliga, S., Fähnle, M. & Schneider, C. M. Ultrafast nanomagnetic toggle switching of vortex cores. Phys. Rev. Lett. 98, 117201 (2007).

  22. 22

    Curcic, M. et al. Polarization selective magnetic vortex dynamics and core reversal in rotating magnetic fields. Phys. Rev. Lett. 101, 197204 (2007).

  23. 23

    Guslienko, K. Y., Lee, K.-S. & Kim, S.-K. Dynamic origin of vortex core switching in soft magnetic nanodots. Phys. Rev. Lett. 100, 027203 (2008).

  24. 24

    Lee K-S. et al. Universal criterion and phase diagram for switching a magnetic vortex core in soft magnetic nanodots. Phys. Rev. Lett. 101, 267206 (2008).

  25. 25

    Kammerer, M. et al. Magnetic vortex core reversal by excitation of spin waves. Nature Commun. 2, 279 (2011).

  26. 26

    Xiao, Q. F., Rudge, J., Choi, B. C., Hong, Y. K. & Donohoe, G. Dynamics of vortex core switching in ferromagnetic nanodisks. Appl. Phys. Lett. 89, 262507 (2006).

  27. 27

    Nakano, K. et al. Real-time observation of electrical vortex core switching. Appl. Phys. Lett. 102, 072405 (2013).

  28. 28

    Guslienko, K. Y., Novosad, V., Otani, Y., Shima, H. & Fukamichi, K. Field evolution of magnetic vortex state in ferromagnetic disks. Appl. Phys. Lett. 78, 3848–3850 (2001).

  29. 29

    Schneider, M., Hoffmann, H. & Zweck, J. Magnetic switching of single vortex permalloy elements. Appl. Phys. Lett. 79, 3113–3115 (2001).

  30. 30

    Yakata, S., Miyata, M., Nonoguchi, S., Wada, H. & Kimura, T. Control of vortex chirality in regular polygonal nanomagnets using in-plane magnetic field. Appl. Phys. Lett. 97, 222503 (2010).

  31. 31

    Jaafar, M. et al. Control of the chirality and polarity of magnetic vortices in triangular nanodots. Phys. Rev. B 81, 054439 (2010).

  32. 32

    Mironov, V. L. et al. MFM probe control of magnetic vortex chirality in elliptical Co nanoparticles. J. Magn. Magn. Mater. 312, 153–157 (2007).

  33. 33

    Gaididei, Y., Sheka, D. D. & Mertens, F. G. Controllable switching of vortex chirality in magnetic nanodisks by a field pulse. Appl. Phys. Lett. 92, 012503 (2008).

  34. 34

    Konoto, M. et al. Formation and control of magnetic vortex chirality in patterned micromagnet arrays. J. Appl. Phys. 103, 023904 (2008).

  35. 35

    Yakata, S. et al. Chirality control of magnetic vortex in a square Py dot using current-induced Oersted field. Appl. Phys. Lett. 99, 242507 (2011).

  36. 36

    Tanase, M. et al. Magnetization reversal in circularly exchange-biased ferromagnetic disks. Phys. Rev. B 79, 014436 (2009).

  37. 37

    Im, M-Y. et al. Symmetry breaking in the formation of magnetic vortex states in a permalloy nanodisk. Nature Commun. 3, 983 (2012).

  38. 38

    Choi, B. C. et al. Spin-current pulse induced switching of vortex chirality in permalloy/Cu/Co nanopillars. Appl. Phys. Lett. 91, 022501 (2007).

  39. 39

    Stoner, E. C. & Wohlfarth, E. P. A mechanism of magnetic hysteresis in heterogeneous alloys. Phil. Trans. R. Soc. Lond. A 240, 599–642 (1948).

  40. 40

    He, L., Doyle, W. D. & Fujiwara, H. High speed coherent switching below the Stoner–Wohlfarth limit. IEEE Trans. Magn. 30, 4086–4088 (1994).

  41. 41

    Fischer, P. et al. Soft X-ray microscopy of nanomagnetism. Mater. Today 9, 26–33 (January–February, 2006).

  42. 42

    Cowburn, R. P., Adeyeye, A. O. & Welland, M. E. Controlling magnetic ordering in coupled nanomagnet arrays. New J. Phys. 1, 16 (1999).

  43. 43

    Natali, M. et al. Correlated magnetic vortex chains in mesoscopic cobalt dot arrays. Phys. Rev. Lett. 88, 157203 (2002).

  44. 44

    Novosad, V. et al. Nucleation and annihilation of magnetic vortices in sub-micron permalloy dots. IEEE Trans. Magn. 37, 2088–2090 (2001).

  45. 45

    Donahue, M. J. & Porter, D. G. OOMMF User's Guide, Version 1.0, Interagency Report NISTIR 6376 (National Institute of Standards and Technology, 1999).

  46. 46

    Cheng, X. M., Buchanan, K. S., Divan, R., Guslienko, K. Y. & Keavney D. J. Nonlinear vortex dynamics and transient domains in ferromagnetic disks. Phys. Rev. B 79, 172411 (2009).

  47. 47

    Park, J. P., Eames, P., Engebretson, D. M., Berezovsky, J. & Crowell, P. A. Imaging of spin dynamics in closure domain and vortex structures. Phys. Rev. B 67, 020403(R) (2003).

  48. 48

    Döring, W. On the inertia of walls between Weiss domains. Z. Naturforsch. 3a, 373–379 (1948).

  49. 49

    Dussaux, A. et al. Field dependence of spin-transfer-induced vortex dynamics in the nonlinear regime. Phys. Rev. B 86, 014402 (2012).

  50. 50

    Chung, S-H., McMichael, R. D., Pierce, D. T. & Unguris, J. Phase diagram of magnetic nanodisks measured by scanning electron microscopy with polarization analysis. Phys. Rev. B 81, 024410 (2010).

  51. 51

    Chang, R., Li, S., Lubarda, M. V., Livshitz, B. & Lomakin, V. FastMag: fast micromagnetic simulator for complex magnetic structures. J. Appl. Phys. 109, 07D358 (2011).

  52. 52

    Escobar, M. A. et al. Advanced micromagnetic analysis of write head dynamics using FastMag. IEEE Trans. Magn. 48, 1731–1737 (2012).

  53. 53

    Kasai, S. et al. Probing the spin polarization of current by soft X-ray imaging of current-induced magnetic vortex dynamics. Phys. Rev. Lett. 101, 237203 (2008).

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The authors thank R. Descoteaux and O. Inac for technical help. The authors also thank M. Escobar and V. Lomakin for help with the FastMag simulations, R. Antoš for useful discussions and J. Sapan for editing the manuscript. The research at UCSD was supported by the research programs of the US Department of Energy (DOE), Office of Basic Energy Sciences (award #DE-SC0003678), and the research at CEITEC BUT by the European Regional Development Fund (CEITEC – CZ.1.05/1.1.00/02.0068) and the Grant Agency of the Czech Republic (project no. P102/12/P443). The operation of the X-ray microscope was supported by the Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the US DOE (contract no. DE-AC02-05-CH11231). Sample nanofabrication was supported by the company TESCAN.

Author information

V.U. and M.U. designed and planned the experiment. M.U. and L.H. fabricated the samples. V.U., M.U., J.S. and T.Š. performed the experiments, with help from M-Y.I., P.F., N.E. and J.J.K. V.U. and M.U. carried out the micromagnetic simulations, analysed the data and prepared the figures. E.E.F. was involved in experimental planning and analysis of the results. V.U. wrote the manuscript. All authors commented on the manuscript.

Correspondence to V. Uhlíř.

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Uhlíř, V., Urbánek, M., Hladík, L. et al. Dynamic switching of the spin circulation in tapered magnetic nanodisks. Nature Nanotech 8, 341–346 (2013) doi:10.1038/nnano.2013.66

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