Two-dimensional mutually synchronized spin Hall nano-oscillator arrays for neuromorphic computing
Source abstract
Abstract
In spin Hall nano-oscillators (SHNOs), pure spin currents drive local regions of magnetic films and nanostructures into auto-oscillating precession. If such regions are placed in close proximity to each other they can interact and may mutually synchronize. Here, we demonstrate robust mutual synchronization of two-dimensional SHNO arrays ranging from 2 × 2 to 8 × 8 nano-constrictions, observed both electrically and using micro-Brillouin light scattering microscopy. On short time scales, where the auto-oscillation linewidth [Formula: see text] is governed by white noise, the signal quality factor, [Formula: see text], increases linearly with the number of mutually synchronized nano-constrictions (N), reaching 170,000 in the largest arrays. We also show that SHNO arrays exposed to two independently tuned microwave frequencies exhibit the same synchronization maps as can be used for neuromorphic vowel recognition. Our demonstrations may hence enable the use of SHNO arrays in two-dimensional oscillator networks for high-quality microwave signal generation and ultra-fast neuromorphic computing.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Magnetic properties of thin films · Neural Networks and Reservoir Computing · Advanced Memory and Neural Computing
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (48)
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1. Grollier, J., Querlioz, D. & Stiles, M. D. Spintronic nanodevices for bioinspired computing. Proc. IEEE 104, 2024–2039 (2016).10.1109/JPROC.2016.2597152 ↗
2. Pufall, M. R. et al. Physical implementation of coherently coupled oscillator networks. IEEE J. Expl. Solid-State Comput. Dev. Circ. 1, 76–84 (2015).
3. Locatelli, N., Cros, V. & Grollier, J. Spin-torque building blocks. Nat. Mater. 13, 11–20 (2014).10.1038/nmat3823 ↗
4. Xu, X. et al. Scaling for edge inference of deep neural networks. Nat. Electron. 1, 216–222 (2018).10.1038/s41928-018-0059-3 ↗
5. Buzsaki, G. Rhythms of the Brain (Oxford Univ. Press, 2006).10.1093/acprof:oso/9780195301069.001.0001 ↗
6. Kumar, S., Strachan, J. P. & Williams, R. S. Chaotic dynamics in nanoscale NBO 2 Mott memristors for analogue computing. Nature 548, 318–321 (2017).10.1038/nature23307 ↗
7. Ignatov, M., Ziegler, M., Hansen, M. & Kohlstedt, H. Memristive stochastic plasticity enables mimicking of neural synchrony: memristive circuit emulates an optical illusion. Sci. Adv. 3, e1700849 (2017).10.1126/sciadv.1700849 ↗
8. Segall, K. et al. Synchronization dynamics on the picosecond time scale in coupled Josephson junction neurons. Phys. Rev. E. 95, 032220 (2017).10.1103/PhysRevE.95.032220 ↗
9. Galin, M. A. et al. Synchronization of large Josephson-junction arrays by traveling electromagnetic waves. Phys. Rev. Appl. 9, 054032 (2018).10.1103/PhysRevApplied.9.054032 ↗
10. Inagaki, T. et al. A coherent Ising machine for 2000-node optimization problems. Science 354, 603–606 (2016).10.1126/science.aah4243 ↗
11. McMahon, P. L. et al. A fully programmable 100-spin coherent Ising machine with all-to-all connections. Science 354, 614–617 (2016).10.1126/science.aah5178 ↗
12. Fang, Y., Yashin, V. V., Levitan, S. P. & Balazs, A. C. Pattern recognition with ‘materials that compute’. Sc. Adv. 2, e1601114 (2016).10.1126/sciadv.1601114 ↗
13. Shim, S.-B., Imboden, M. & Mohanty, P. Synchronized oscillation in coupled nanomechanical oscillators. Science 316, 95–99 (2007).10.1126/science.1137307 ↗
14. Csaba, G. & Porod, W. Computational study of spin-torque oscillator interactions for non-Boolean computing applications. IEEE Trans. Magnet. 49, 4447–4451 (2013).10.1109/TMAG.2013.2244202 ↗
15. Yogendra, K., Fan, D., Jung, B. & Roy, K. Magnetic pattern recognition using injection-locked spin-torque nano-oscillators. IEEE Trans. Electron Dev. 63, 1674–1680 (2016).10.1109/TED.2016.2523423 ↗
16. Chen, T. et al. Spin-torque and spin-Hall nano-oscillators. Proc. IEEE 104, 1919–1945 (2016).10.1109/JPROC.2016.2554518 ↗
17. Rippard, W. H., Pufall, M. R., Kaka, S., Silva, T. J. & Russek, S. E. Current-driven microwave dynamics in magnetic point contacts as a function of applied field angle. Phys. Rev. B. 70, 100406 (2004).10.1103/PhysRevB.70.100406 ↗
18. Romera, M. et al. Vowel recognition with four coupled spin-torque nano-oscillators. Nature 563, 230–234 (2018).10.1038/s41586-018-0632-y ↗
19. Demidov, V. E. et al. Magnetic nano-oscillator driven by pure spin current. Nat. Mater. 11, 1028–1031 (2012).10.1038/nmat3459 ↗
20. Ranjbar, M. CoFeB-based spin Hall nano-oscillators. IEEE Magnet. Lett. 5, 1–4 (2014).10.1109/LMAG.2014.2375155 ↗
21. Zahedinejad, M. et al. CMOS compatible w/cofeb/mgo spin Hall nano-oscillators with wide frequency tunability. Appl. Phys. Lett. 112, 132404 (2018).10.1063/1.5022049 ↗
22. Demidov, V. E. et al. Magnetic nano-oscillator driven by pure spin current. Nat. Mater. 11, 1028–1031 (2012).10.1038/nmat3459 ↗
23. Demidov, V. E., Urazhdin, S., Zholud, A., Sadovnikov, A. V. & Demokritov, S. O. Nanoconstriction-based spin-Hall nano-oscillator. Appl. Phys. Lett. 105, 172410 (2014).10.1063/1.4901027 ↗
24. Fulara, H. et al. Spin-orbit torque–driven propagating spin waves. Sci. Adv. 5, eaax8467 (2019).10.1126/sciadv.aax8467 ↗
25. Awad, A. et al. Long-range mutual synchronization of spin Hall nano-oscillators. Nat. Phys. 13, 292–299 (2017).10.1038/nphys3927 ↗
26. Kim, J.-V., Tiberkevich, V. & Slavin, A. Generation linewidth of an auto-oscillator with a nonlinear frequency shift: spin-torque nano-oscillator. Phys. Rev. Lett. 100, 1–4 (2008).
27. Mazraati, H., Zahedinejad, M. & Åkerman, J. Improving the magnetodynamical properties of Nife/Pt bilayers through HF dusting. Appl. Phys. Lett. 113, 092401 (2018).10.1063/1.5026232 ↗
28. Dvornik, M., Awad, A. A. & Åkerman, J. Origin of magnetization auto-oscillations in constriction-based spin Hall nano-oscillators. Phys. Rev. Appl. 9, 014017 (2018).10.1103/PhysRevApplied.9.014017 ↗
29. Keller, M. W., Pufall, M. R., Rippard, W. H. & Silva, T. J. Nonwhite frequency noise in spin torque oscillators and its effect on spectral linewidth. Phys. Rev. B. 82, 054416 (2010).10.1103/PhysRevB.82.054416 ↗
30. Georges, B., Grollier, J., Cros, V. & Fert, A. Impact of the electrical connection of spin transfer nano-oscillators on their synchronization: an analytical study. Appl. Phys. Lett. 92, 232504 (2008).10.1063/1.2945636 ↗
31. Tamaru, S., Kubota, H., Yakushiji, K., Yuasa, S. & Fukushima, A. Extremely coherent microwave emission from spin torque oscillator stabilized by phase locked loop. Sci. Rep. 5, 18134 (2015).10.1038/srep18134 ↗
32. Demidov, V. et al. Synchronization of spin Hall nano-oscillators to external microwave signals. Nat. Commun. 5, 3179 (2014).10.1038/ncomms4179 ↗
33. Matsukura, F., Tokura, Y. & Ohno, H. Control of magnetism by electric fields. Nat. Nanotech. 10, 209–220 (2015).10.1038/nnano.2015.22 ↗
34. Liu, R., Chen, L., Urazhdin, S. & Du, Y. et al. Controlling the spectral characteristics of a spin-current auto-oscillator with an electric field. Phys. Rev. App. 8, 021001 (2017).10.1103/PhysRevApplied.8.021001 ↗
35. Mishra, R. et al. Electric-field control of spin accumulation direction for spin-orbit torques. Nat. Commun. 10, 248 (2019).10.1038/s41467-018-08274-8 ↗
36. Mishra, R., Kumar, D. & Yang, H. Oxygen-migration-based spintronic device emulating a biological synapse. Phys. Rev. Appl. 11, 054065 (2019).10.1103/PhysRevApplied.11.054065 ↗
37. Parihar, A., Shukla, N., Jerry, M., Datta, S. & Raychowdhury, A. Vertex coloring of graphs via phase dynamics of coupled oscillatory networks. Sci. Rep. 7, 911 (2017).10.1038/s41598-017-00825-1 ↗
38. Velichko, A., Belyaev, M. & Boriskov, P. A model of an oscillatory neural network with multilevel neurons for pattern recognition and computing. Electronics 8, 75 (2019).10.3390/electronics8010075 ↗
39. Zhang, T., Haider, M., Massoud, Y. & Alexander, J. An oscillatory neural network based local processing unit for pattern recognition applications. Electronics 8, 64 (2019).10.3390/electronics8010064 ↗
40. Kumar, A. & Mohanty, P. Autoassociative memory and pattern recognition in micromechanical oscillator network. Sci. Rep. 7, 411 (2017).
41. Nikonov, D. E. et al. Coupled-oscillator associative memory array operation for pattern recognition. IEEE J. Expl. Solid-State Comput. Dev. Circ. 1, 85–93 (2015).
42. Fang, Y., Yashin, V. V., Jennings, B. B., Chiarulli, D. M. & Levitan, S. P. A simplified phase model for simulation of oscillator-based computing systems. ACM J. Emerg. Tech. Comput. Syst. 13, 14 (2017).10.1145/2976743 ↗
43. Novikov, A. & Benderskaya, E. in International Conference on Parallel Computing Technologies (ed Malyshki, V.) 210–221 (Springer, 2015).10.1007/978-3-319-21909-7_20 ↗
44. Wang, T., Wu, L. & Roychowdhury, J. New computational results and hardware prototypes for oscillator-based Ising machines. In Proc. 56th Annual Design Automation Conference 2019 239 (ACM, 2019).10.1145/3316781.3322473 ↗
45. Dürrenfeld, P., Awad, A. A., Houshang, A., Dumas, R. K. & Åkerman, J. A 20 nm spin Hall nano-oscillator. Nanoscale 9, 1285–1291 (2017).10.1039/C6NR07903B ↗
46. Lebrun, R. et al. Mutual synchronization of spin torque nano-oscillators through a long-range and tunable electrical coupling scheme. Nat. Commun. 8, 15825 (2017).10.1038/ncomms15825 ↗
47. Tsunegi, S. et al. Scaling up electrically synchronized spin torque oscillator networks. Sci. Rep. 8, 13475 (2018).10.1038/s41598-018-31769-9 ↗
48. Wiesenfeld, K., Benz, S. P. & Booi, P. Phase-locked oscillator optimization for arrays of Josephson junctions. J. Appl. Phys. 76, 3835–3846 (1994).10.1063/1.357387 ↗