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Chiral Magnetic Domain Wall and Skyrmion Memory Devices

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Emerging Non-volatile Memory Technologies

Abstract

In the chapter, we have reviewed the fundamental physics for designing magnetic domain wall memories, especially domain wall racetrack memories. An overview of how the racetrack has been functionally improved and the fundamental physics behind the operating mechanism has developed is shown. Material wise, the design of the racetrack has changed from using in-plane magnetic materials to out-of-plane magnetic materials. The process of changing the material design resulted in new physics such as the spin-orbit torques (SOTs) and the Dzyaloshinskii-Moriya interaction (DMI) which resulted in domain wall motion with higher efficiency and stability. The SOT is the main mechanism in moving the domain walls efficiently by utilizing the spin Hall effect (SHE) and the inverse spin galvanic effect (ISGE) which have shown to be more efficient than the spin-transfer torque (STT) in current induced domain wall motion. The exact physics behind the SOTs is still not well known, but it was well demonstrated that the SOTs show higher efficiency for domain wall (DW) motion. However, this SOT requires additionally a chiral symmetry breaking such as due to DMI in order to act on the DWs. The DMI generates a certain chirality for the domain walls, especially forcing a chiral Néel type DW. The Néel DW is required for the SOT to act as a driving force of the DWs. The different sections of the chapter have reviewed the different physics and evidence of the SOT and DMI with the different experimental methods to quantify the SOT and DMI. Furthermore, as an outlook for the racetrack memory, we have reviewed the new exciting skyrmion racetrack memory which can be a future implementation of the racetrack memory.

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References

  1. S.S.P. Parkin, M. Hayashi, L. Thomas, Magnetic domain-wall racetrack memory. Science 320, 190 (2008)

    Google Scholar 

  2. J.-S. Kim et al., Synchronous precessional motion of multiple domain walls in a ferromagnetic nanowire by perpendicular field pulses. Nat. Commun. 5, 3429 (2014)

    Article  ADS  Google Scholar 

  3. T.A. Moore et al., Magnetic-field-induced domain-wall motion in permalloy nanowires with modified Gilbert damping. Phys. Rev. B 82, 094445 (2010)

    Article  ADS  Google Scholar 

  4. J.C. Slonczewski, Current-driven excitation of magnetic multilayers. J. Magn. Magn. Mater. 159, L1–L7 (1996)

    Article  ADS  Google Scholar 

  5. L. Berger, Emission of spin waves by a magnetic multilayer traversed by a current. Phys. Rev. B 54, 9353–9358 (1996)

    Article  ADS  Google Scholar 

  6. A. Brataas, A.D. Kent, H. Ohno, Current-induced torques in magnetic materials. Nat. Mater. 11, 372–381 (2012)

    Article  ADS  Google Scholar 

  7. M. Hayashi et al., Current driven domain wall velocities exceeding the spin angular momentum transfer rate in permalloy nanowires. Phys. Rev. Lett. 98, 037204 (2007)

    Article  ADS  Google Scholar 

  8. A. Thiaville, Y. Nakatani, J. Miltat, Y. Suzuki, Micromagnetic understanding of current-driven domain wall motion in patterned nanowires. EPL 69, 990 (2005)

    Article  ADS  Google Scholar 

  9. M. Kläui, Head-to-head domain walls in magnetic nanostructures. J. Phys. Condens. Matter 20, 313001 (2008)

    Article  ADS  Google Scholar 

  10. O. Boulle, G. Malinowski, M. Kläui, Current-induced domain wall motion in nanoscale ferromagnetic elements. Mater. Sci. Eng. R Reports 72, 159–187 (2011)

    Article  Google Scholar 

  11. O. Boulle et al., Nonadiabatic spin transfer torque in high anisotropy magnetic nanowires with narrow domain walls. Phys. Rev. Lett. 101, 216601 (2008)

    Article  ADS  Google Scholar 

  12. T. Koyama et al., Observation of the intrinsic pinning of a magnetic domain wall in a ferromagnetic nanowire. Nat. Mater. 10, 194–197 (2011)

    Article  ADS  Google Scholar 

  13. D. Ravelosona, D. Lacour, J.A. Katine, B.D. Terris, C. Chappert, Nanometer scale observation of high efficiency thermally assisted current-driven domain wall depinning. Phys. Rev. Lett. 95, 117203 (2005)

    Article  ADS  Google Scholar 

  14. T. Suzuki, S. Fukami, K. Nagahara, N. Ohshima, N. Ishiwata, Current-driven domain wall motion, nucleation, and propagation in a Co/Pt multi-layer strip with a stepped structure. IEEE Trans. Magn. 44, 2535–2538 (2008)

    Article  ADS  Google Scholar 

  15. T.A. Moore et al., High domain wall velocities induced by current in ultrathin Pt/Co/AlOx wires with perpendicular magnetic anisotropy. Appl. Phys. Lett. 93, 262504–212404 (2008)

    Article  ADS  Google Scholar 

  16. I.M. Miron et al., Domain wall spin torquemeter. Phys. Rev. Lett. 102, 137202 (2009)

    Article  ADS  Google Scholar 

  17. M. Cormier et al., Effect of electrical current pulses on domain walls in Pt/Co/Pt nanotracks with out-of-plane anisotropy: spin transfer torque versus Joule heating. Phys. Rev. B 81, 024407 (2010)

    Article  ADS  Google Scholar 

  18. R. Lavrijsen et al., Asymmetric Pt/Co/Pt-stack induced sign-control of current-induced magnetic domain-wall creep. Appl. Phys. Lett. 100, 262408 (2012)

    Article  ADS  Google Scholar 

  19. S. Parkin, S.-H. Yang, Memory on the racetrack. Nat. Nanotechnol. 10, 195–198 (2015)

    Article  ADS  Google Scholar 

  20. S. Emori, U. Bauer, S.-M. Ahn, E. Martinez, G.S.D. Beach, Current-driven dynamics of chiral ferromagnetic domain walls. Nat. Mater. 12, 611–616 (2013)

    Article  ADS  Google Scholar 

  21. S.D. Ganichev et al., Spin-galvanic effect. Nature 417, 153–156 (2002)

    Article  ADS  Google Scholar 

  22. Y.A. Bychkov, E.I. Rashba, Properties of a 2D electron gas with lifted spectral degeneracy. SovJEPT Lett. 39, 78–81 (1984)

    ADS  Google Scholar 

  23. S. Zhang, P.M. Levy, A. Fert, Mechanisms of spin-polarized current-driven magnetization switching. Phys. Rev. Lett. 88, 236601 (2002)

    Article  ADS  Google Scholar 

  24. I. M. Miron et al., Current-driven spin torque induced by the Rashba effect in a ferromagnetic metal layer. Nat. Mater. 9, 230 (2010)

    Article  ADS  Google Scholar 

  25. I.M. Miron et al., Fast current-induced domain-wall motion controlled by the Rashba effect. Nat. Mater. 10, 419–423 (2011)

    Article  ADS  Google Scholar 

  26. M. Kavand et al, Quantitative inverse spin hall effect detection via precise control of the driving-field amplitude. Phys. Rev. B—Condens. Matter Mater. Phys. 95, 161406(R) (2017)

    Google Scholar 

  27. L. Liu, T. Moriyama, D.C. Ralph, R.A. Buhrman, Spin-torque ferromagnetic resonance induced by the spin hall effect. Phys. Rev. Lett. 106, 036601 (2011)

    Article  ADS  Google Scholar 

  28. J. Sinova, S.O. Valenzuela, J. Wunderlich, C.H. Back, T. Jungwirth, Spin hall effects. Rev. Mod. Phys. 87, 1213–1260 (2015)

    Article  ADS  Google Scholar 

  29. M.I. Dyakonov, V.I. Perel, Current-induced spin orientation of electrons in semiconductors. Phys. Lett. A 35, 459–460 (1971)

    Article  ADS  Google Scholar 

  30. J.E. Hirsch, Spin hall effect. Phys. Rev. Lett. 83, 1834–1837 (1999)

    Article  ADS  Google Scholar 

  31. S. Murakami, N. Nagaosa, S.-C. Zhang, Dissipationless quantum spin current at room temperature. Science (80-. ). 301, 1348 LP–1351 (2003)

    Google Scholar 

  32. J. Sinova et al., Universal intrinsic spin hall effect. Phys. Rev. Lett. 92, 126603 (2004)

    Article  ADS  Google Scholar 

  33. N.F. Mott, On the interpretation of the relativity wave equation for two electrons. Proc. R. Soc. London. Ser. A 124, 422LP–425 (1929)

    Article  ADS  Google Scholar 

  34. N.F. Mott, The polarisation of electrons by double scattering. Proc. R. Soc. London. Ser. A 135, 429LP–458 (1932)

    Article  ADS  MATH  Google Scholar 

  35. A. Crépieux, P. Bruno, Relativistic corrections in magnetic systems. Phys. Rev. B 64, 94434 (2001)

    Article  ADS  Google Scholar 

  36. J.C. Sankey et al., Measurement of the spin-transfer-torque vector in magnetic tunnel junctions. Nat. Phys. 4, 67–71 (2008)

    Article  Google Scholar 

  37. W. Zhang, W. Han, X. Jiang, S.-H. Yang, S.S.P. Parkin, Role of transparency of platinum–ferromagnet interfaces in determining the intrinsic magnitude of the spin Hall effect. Nat. Phys. 11, 496–502 (2015)

    Article  Google Scholar 

  38. T. Nan et al., Comparison of spin-orbit torques and spin pumping across NiFe/Pt and NiFe/Cu/Pt interfaces. Phys. Rev. B 91, 214416 (2015)

    Article  ADS  Google Scholar 

  39. J. Kim et al., Spin-orbit torques associated with ferrimagnetic order in Pt/GdFeCo/MgO layers. Sci. Rep. 8, 6017 (2018)

    Article  ADS  Google Scholar 

  40. S. Woo, M. Mann, A.J. Tan, L. Caretta, G.S.D. Beach, Enhanced spin-orbit torques in Pt/Co/Ta heterostructures. Appl. Phys. Lett. 105, 162507–122404 (2014)

    Article  Google Scholar 

  41. J. Kim et al., Layer thickness dependence of the current-induced effective field vector in Ta|CoFeB|MgO. Nat. Mater. 12, 240–245 (2012)

    Article  ADS  Google Scholar 

  42. K. Garello et al., Symmetry and magnitude of spin–orbit torques in ferromagnetic heterostructures. Nat. Nanotechnol. 8, 587–593 (2013)

    Article  ADS  Google Scholar 

  43. Y. Fan et al., Magnetization switching through giant spin–orbit torque in a magnetically doped topological insulator heterostructure. Nat. Mater. 13, 699–704 (2014)

    Article  ADS  Google Scholar 

  44. A. Thiaville, S. Rohart, E. Jue, V. Cros, A. Fert, Dynamics of Dzyaloshinskii domain walls in ultrathin magnetic films. EPL 100, 57002 (2012)

    Article  ADS  Google Scholar 

  45. T. Schulz et al., Effective field analysis using the full angular spin-orbit torque magnetometry dependence. Phys. Rev. B 95, 224409 (2017)

    Article  ADS  Google Scholar 

  46. L. Liu, O.J. Lee, T.J. Gudmundsen, D.C. Ralph, R.A. Buhrman, Current-induced switching of perpendicularly magnetized magnetic layers using spin torque from the spin hall effect. Phys. Rev. Lett. 109, 096602 (2012)

    Google Scholar 

  47. J. Heinen et al., Determination of the spin torque non-adiabaticity in perpendicularly magnetized nanowires. J. Phys. Condens. Matter 24, 24220 (2012)

    Article  Google Scholar 

  48. T. Schulz et al., Spin-orbit torques for current parallel and perpendicular to a domain wall. Appl. Phys. Lett. 107, 122405 (2015)

    Article  ADS  Google Scholar 

  49. C. Zhang, S. Fukami, H. Sato, F. Matsukura, H. Ohno, Spin-orbit torque induced magnetization switching in nano-scale Ta/CoFeB/MgO. Appl. Phys. Lett. 107, 122405–222401 (2015)

    Google Scholar 

  50. P.P.J. Haazen et al., Domain wall depinning governed by the spin Hall effect. Nat. Mater. 12, 299–303 (2013)

    Article  ADS  Google Scholar 

  51. R. Lo Conte et al., Role of B diffusion in the interfacial Dzyaloshinskii-Moriya interaction in Ta/Co20Fe60B20/MgO nanowires. Phys. Rev. B 91, 14433 (2015)

    Article  ADS  Google Scholar 

  52. I. Dzyaloshinsky, A thermodynamic theory of “weak” ferromagnetism of antiferromagnetics. J. Phys. Chem. Solids 4, 241–255 (1958)

    Article  ADS  Google Scholar 

  53. T. Moriya, Anisotropic superexchange interaction and weak ferromagnetism. Phys. Rev. 120, 91–98 (1960)

    Article  ADS  Google Scholar 

  54. S. Mühlbauer et al., Skyrmion lattice in a chiral magnet. Science (80-. ) 323, 915 (2009)

    Google Scholar 

  55. S.X. Huang, C.L. Chien, Extended skyrmion phase in epitaxial FeGe (111) Thin Films. Phys. Rev. Lett. 108, 267201 (2012)

    Article  ADS  Google Scholar 

  56. S. Rohart, A. Thiaville, Skyrmion confinement in ultrathin film nanostructures in the presence of Dzyaloshinskii-Moriya interaction. Phys. Rev. B 88, 184422 (2013)

    Article  ADS  Google Scholar 

  57. B. Krüger, M. Kläui topological defects in nanostructures---chiral domain walls and skyrmions. in Topological Structures in Ferroic Materials: Domain Walls, Vortices and Skyrmions ed. by J. Seidel (Springer International Publishing, 2016) pp. 199–218

    Google Scholar 

  58. F. Büttner, M. Kläui, Chapter 8 magnetic skyrmion dynamics. in Skyrmions: Topological Structures, Properties, and Applications (CRC Press, 2016), pp. 211–238

    Google Scholar 

  59. M. Bode et al., Chiral magnetic order at surfaces driven by inversion asymmetry. Nature 447, 190–193 (2007)

    Article  ADS  Google Scholar 

  60. G. Chen et al., Novel chiral magnetic domain wall structure in Fe/Ni / Cu (001) films. Phys. Rev. Lett. 110, 177204 (2013)

    Article  ADS  Google Scholar 

  61. S.G. Je et al., Asymmetric magnetic domain-wall motion by the Dzyaloshinskii-Moriya interaction. Phys. Rev. B 88, 214401 (2013)

    Article  ADS  Google Scholar 

  62. M. Vaňatka et al., Velocity asymmetry of Dzyaloshinskii domain walls in the creep and flow regimes. J. Phys. Condens. Matter 27, 326002 (2015)

    Article  Google Scholar 

  63. A. Hrabec et al., Measuring and tailoring the Dzyaloshinskii-Moriya interaction in perpendicularly magnetized thin films. Phys. Rev. B 90, 020402 (2014)

    Article  ADS  Google Scholar 

  64. K.-S. Ryu, L. Thomas, S.-H. Yang, S. Parkin, Chiral spin torque at magnetic domain walls. Nat. Nanotechnol. 8, 527–533 (2013)

    Article  ADS  Google Scholar 

  65. J. Torrejon et al., Interface control of the magnetic chirality in CoFeB/MgO heterostructures with heavy-metal underlayers. Nat. Commun. 5, 144425 (2014)

    Article  Google Scholar 

  66. D.-Y. Kim et al., Chirality-induced antisymmetry in magnetic domain wall speed. NPG Asia Mater. 10, e464–e464 (2018)

    Article  ADS  Google Scholar 

  67. D.-Y. Kim et al., Magnetic domain-wall tilting due to domain-wall speed asymmetry. Phys. Rev. B 97, 134407 (2018)

    Article  ADS  Google Scholar 

  68. E. Jué et al., Chiral damping of magnetic domain walls. Nat. Mater. 15, 272 (2015)

    Article  ADS  Google Scholar 

  69. J. Cho et al., Thickness dependence of the interfacial Dzyaloshinskii-Moriya interaction in inversion symmetry broken systems. Nat. Commun. 6, 7635 (2015)

    Article  ADS  Google Scholar 

  70. N.H. Kim et al., Interfacial Dzyaloshinskii-Moriya interaction, surface anisotropy energy, and spin pumping at spin orbit coupled Ir/Co interface. Appl. Phys. Lett. 108, 142406–152403 (2016)

    Article  ADS  Google Scholar 

  71. N.H. Kim et al., Improvement of the interfacial Dzyaloshinskii-Moriya interaction by introducing a Ta buffer layer. Appl. Phys. Lett. 107, 142408–152403 (2015)

    Article  ADS  Google Scholar 

  72. H.T. Nembach, J.M. Shaw, M. Weiler, E. Jué, T.J. Silva, Linear relation between heisenberg exchange and interfacial Dzyaloshinskii-Moriya interaction in metal films. Nat. Phys. 11, 825–829 (2015)

    Article  Google Scholar 

  73. H.S. Körner et al., Interfacial Dzyaloshinskii-Moriya interaction studied by time-resolved scanning kerr microscopy. Phys. Rev. B 92, 220413 (2015)

    Article  ADS  Google Scholar 

  74. K. Zakeri et al., Asymmetric spin-wave dispersion on Fe(110): direct evidence of the Dzyaloshinskii-Moriya interaction. Phys. Rev. Lett. 104, 137203 (2010)

    Article  ADS  Google Scholar 

  75. J.M. Lee et al., All-electrical measurement of interfacial dzyaloshinskii-moriya interaction using collective spin-wave dynamics. Nano Lett. 16, 62–67 (2016)

    Article  ADS  Google Scholar 

  76. J.R. Eshbach, R.W. Damon, Surface magnetostatic modes and surface spin waves. Phys. Rev. 118, 1208–1210 (1960)

    Article  ADS  Google Scholar 

  77. S. Woo et al., Observation of room-temperature magnetic skyrmions and their current-driven dynamics in ultrathin metallic ferromagnets. Nat. Mater. 15, 501–506 (2016)

    Article  ADS  Google Scholar 

  78. D.S. Han et al., Asymmetric hysteresis for probing Dzyaloshinskii-moriya interaction. Nano Lett. 16, 4438–4446 (2016)

    Article  ADS  Google Scholar 

  79. A. Fert, V. Cros, J. Sampaio, Skyrmions on the track. Nat. Nanotechnol. 8, 152–156 (2013)

    Article  ADS  Google Scholar 

  80. J. Müller, Magnetic skyrmions on a two-lane racetrack. New J. Phys. 19, 25002 (2017)

    Article  Google Scholar 

  81. F. Buttner et al., Dynamics and inertia of skyrmionic spin structures. Nat. Phys. 11, 225–228 (2015)

    Article  Google Scholar 

  82. K. Litzius et al., Skyrmion Hall effect revealed by direct time-resolved X-ray microscopy. Nat. Phys. 13, 170–175 (2016)

    Article  Google Scholar 

  83. J. Zázvorka et al., Thermal skyrmion diffusion used in a reshuffler device. Nat. Nanotechnol. 14, 658–661 (2019)

    Article  ADS  Google Scholar 

  84. J. Sampaio, V. Cros, S. Rohart, A. Thiaville, A. Fert, Nucleation, stability and current-induced motion of isolated magnetic skyrmions in nanostructures. Nat. Nanotechnol. 8, 839–844 (2013)

    Article  ADS  Google Scholar 

  85. R. Tomasello et al., A strategy for the design of skyrmion racetrack memories. Sci. Rep. 4, 6784 (2014)

    Article  Google Scholar 

  86. S. Zhang et al., Topological computation based on direct magnetic logic communication. Sci. Rep. 5, 15773 (2015)

    Article  ADS  Google Scholar 

  87. X. Zhang et al., Skyrmion-skyrmion and skyrmion-edge repulsions in skyrmion-based racetrack memory. Sci. Rep. 5, 7643 (2015)

    Article  Google Scholar 

  88. G. Finocchio, F. Büttner, R. Tomasello, M. Carpentieri, M. Kläui, Magnetic skyrmions: from fundamental to applications. J. Phys. D. Appl. Phys. 49, 423001 (2016)

    Article  ADS  Google Scholar 

  89. W. Jiang et al, Blowing magnetic skyrmion bubbles. Science (80-.) 349, 283 (2015)

    Google Scholar 

  90. C. Moreau-Luchaire et al., Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmions at room temperature. Nat. Nanotechnol. 11, 444–448 (2016)

    Article  ADS  Google Scholar 

  91. O. Boulle et al., Room temperature chiral magnetic skyrmion in ultrathin magnetic nanostructures. Nat. Nanotechnol. 11, 449–454 (2016)

    Article  ADS  Google Scholar 

  92. X.Z. Yu et al., Skyrmion flow near room temperature in an ultralow current density. Nat. Commun. 3, 988 (2012)

    Article  ADS  Google Scholar 

  93. T. Schulz et al., Emergent electrodynamics of skyrmions in a chiral magnet. Nat. Phys. 8, 301–304 (2012)

    Article  Google Scholar 

  94. K. Everschor, M. Garst, R.A. Duine, A. Rosch, Current-induced rotational torques in the skyrmion lattice phase of chiral magnets. Phys. Rev. B 84, 064401 (2011)

    Article  ADS  Google Scholar 

  95. J. Iwasaki, M. Mochizuki, N. Nagaosa, Universal current-velocity relation of skyrmion motion in chiral magnets. Nat. Commun. 4, 1463 (2013)

    Article  ADS  Google Scholar 

  96. J. Iwasaki, M. Mochizuki, N. Nagaosa, Current-induced skyrmion dynamics in constricted geometries. Nat. Nanotechnol. 8, 742–747 (2013)

    Article  ADS  Google Scholar 

  97. I. Makhfudz, B. Krüger, O. Tchernyshyov, Inertia and chiral edge modes of a skyrmion magnetic bubble. Phys. Rev. Lett. 109, 217201 (2012)

    Article  ADS  Google Scholar 

  98. X. Zhang, Y. Zhou, M. Ezawa, Magnetic bilayer-skyrmions without skyrmion Hall effect. Nat. Commun. 69, 990 (2015)

    Google Scholar 

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  1. Johannes Gutenberg University of Mainz, Mainz, Germany

    Kyujoon Lee, Dong-Soo Han & Mathias Kläui

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  1. Kyujoon Lee
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  2. Dong-Soo Han
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  1. School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore

    Wen Siang Lew

  2. School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore

    Gerard Joseph Lim

  3. School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore

    Putu Andhita Dananjaya

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Lee, K., Han, DS., Kläui, M. (2021). Chiral Magnetic Domain Wall and Skyrmion Memory Devices. In: Lew, W.S., Lim, G.J., Dananjaya, P.A. (eds) Emerging Non-volatile Memory Technologies. Springer, Singapore. https://doi.org/10.1007/978-981-15-6912-8_5

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