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Integrated all-photonic non-volatile multi-level memory

Nature Photonics volume 9, pages 725732 (2015) | Download Citation

Abstract

Implementing on-chip non-volatile photonic memories has been a long-term, yet elusive goal. Photonic data storage would dramatically improve performance in existing computing architectures1 by reducing the latencies associated with electrical memories2 and potentially eliminating optoelectronic conversions3. Furthermore, multi-level photonic memories with random access would allow for leveraging even greater computational capability4,5,6. However, photonic memories3,7,8,9,10 have thus far been volatile. Here, we demonstrate a robust, non-volatile, all-photonic memory based on phase-change materials. By using optical near-field effects, we realize bit storage of up to eight levels in a single device that readily switches between intermediate states. Our on-chip memory cells feature single-shot readout and switching energies as low as 13.4 pJ at speeds approaching 1 GHz. We show that individual memory elements can be addressed using a wavelength multiplexing scheme. Our multi-level, multi-bit devices provide a pathway towards eliminating the von Neumann bottleneck and portend a new paradigm in all-photonic memory and non-conventional computing.

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References

  1. 1.

    & Why future supercomputing requires optics. Nature Photon. 4, 261–263 (2010).

  2. 2.

    & Memory grows up. Nature Nanotech. 5, 177–178 (2010).

  3. 3.

    et al. Large-scale integration of wavelength-addressable all-optical memories on a photonic crystal chip. Nature Photon. 8, 474–481 (2014).

  4. 4.

    et al. An upconverted photonic nonvolatile memory. Nature Commun. 5, 4720 (2014).

  5. 5.

    & The parallel approach. Nature Phys. 9, 200–202 (2013).

  6. 6.

    & Optical computing: photonic neural networks. Nature Phys. 8, 257–259 (2012).

  7. 7.

    et al. A fast low-power optical memory based on coupled micro-ring lasers. Nature 432, 11–14 (2004).

  8. 8.

    A semiconductor-based photonic memory cell. Science 283, 1292–1295 (1999).

  9. 9.

    , , , & Trapping and delaying photons for one nanosecond in an ultrasmall high-Q photonic-crystal nanocavity. Nature Photon. 1, 49–52 (2007).

  10. 10.

    , & An ultra-small, low-power, all-optical flip-flop memory on a silicon chip. Nature Photon. 4, 182–187 (2010).

  11. 11.

    Silicon Photonics: The State of the Art (Springer, 2008).

  12. 12.

    , & Low-cost and nanoscale non-volatile memory concept for future silicon chips. Nature Mater. 4, 347–352 (2005).

  13. 13.

    , & Beyond von-Neumann computing with nanoscale phase-change memory devices. Adv. Funct. Mater. 23, 2248–2254 (2013).

  14. 14.

    , , & Phase change materials and phase change memory. MRS Bull. 39, 703–710 (2014).

  15. 15.

    & Phase-change materials for rewriteable data storage. Nature Mater. 6, 824–832 (2007).

  16. 16.

    et al. Phase change memory technology. J. Vac. Sci. Technol. B 28, 223–262 (2010).

  17. 17.

    Reversible electrical switching phenomena in disordered structures. Phys. Rev. Lett. 21, 1450–1453 (1968).

  18. 18.

    et al. Ultrafast characterization of phase-change material crystallization properties in the melt-quenched amorphous phase. Nano Lett. 14, 3419–3426 (2014).

  19. 19.

    et al. Interfacial phase-change memory. Nature Nanotech. 6, 501–505 (2011).

  20. 20.

    , & Highly scalable non-volatile and ultra-low-power phase-change nanowire memory. Nature Nanotech. 2, 626–630 (2007).

  21. 21.

    & Structure of laser-crystallized Ge2Sb2+xTe5 sputtered thin films for use in optical memory. J. Appl. Phy. 88, 7020–7028 (2000).

  22. 22.

    , & An optoelectronic framework enabled by low-dimensional phase-change films. Nature 511, 206–211 (2014).

  23. 23.

    , , , & On-chip photonic memory elements employing phase-change materials. Adv. Mater. 26, 1372–1377 (2013).

  24. 24.

    et al. Optical switching at 1.55 μm in silicon racetrack resonators using phase change materials. Appl. Phys. Lett. 103, 141119 (2013).

  25. 25.

    et al. Small-sized optical gate switch using Ge2Sb2Te5 phase-change material integrated with silicon waveguide. Electron. Lett. 46, 368 (2010).

  26. 26.

    & Photonic non-volatile memories using phase change materials. Appl. Phys. Lett. 101, 171101 (2012).

  27. 27.

    et al. Breaking the speed limits of phase-change memory. Science 336, 1566–1569 (2012).

  28. 28.

    , , , & Rewritable phase-change optical recording in Ge2Sb2Te5 films induced by picosecond laser pulses. Appl. Phys. Lett. 84, 2250 (2004).

  29. 29.

    et al. Phase change memory. Proc. IEEE 98, 2201–2227 (2010).

  30. 30.

    et al. Programming algorithms for multilevel phase-change memory. Proc. IEEE Int. Symp. Circuits Syst. 329–332 (2011).

  31. 31.

    & Silicon-based on-chip multiplexing technologies and devices for peta-bit optical interconnects. Nanophotonics 3, 1–30 (2013).

  32. 32.

    , , & Ultra-compact wavelength division multiplexing devices using silicon photonic wires for on-chip interconnects. Proc. OFC/NFOEC 2007–2007 Conf. Opt. Fiber Commun. Natl. Fiber Opt. Eng. Conf. OWG2 (2007);

  33. 33.

    et al. A million spiking-neuron integrated circuit with a scalable communication network and interface. Science 345, 614–616 (2014).

  34. 34.

    , , , & Arithmetic and biologically-inspired computing using phase-change materials. Adv. Mater. 23, 3408–3413 (2011).

Download references

Acknowledgements

The authors acknowledge support by Deutsche Forschungsgemeinschaft (DFG) grants PE 1832/1-1 and PE 1832/2-1 and EPSRC grant EP/J018783/1. C.R. is grateful to JEOL UK and the Clarendon Fund for funding his graduate studies. M.S. acknowledges support from the Karlsruhe School of Optics and Photonics (KSOP) and the Stiftung der Deutschen Wirtschaft (sdw). H.B. acknowledges support from the John Fell Fund and the EPSRC (EP/J00541X/2 and EP/J018694/1).The authors also acknowledge support from the DFG and the State of Baden-Württemberg through the DFG-Center for Functional Nanostructures (CFN) within subproject A6.4. This work was partly carried out with the support of the Karlsruhe Nano Micro Facility (KNMF, http://www.knmf.kit.edu), a Helmholtz Research Infrastructure at Karlsruhe Institute of Technology (KIT, http://www.kit.edu). The authors thank S. Diewald for assistance with device fabrication and M. Blaicher for technical assistance with device design.

Author information

Author notes

    • Carlos Ríos
    •  & Matthias Stegmaier

    These authors contributed equally to this work

Affiliations

  1. Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK

    • Carlos Ríos
    • , Peiman Hosseini
    •  & Harish Bhaskaran
  2. Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany

    • Matthias Stegmaier
    • , Di Wang
    • , Torsten Scherer
    •  & Wolfram H. P. Pernice
  3. Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany

    • Di Wang
    •  & Torsten Scherer
  4. Department of Engineering, University of Exeter, Exeter EX4 4QF, UK

    • C. David Wright
  5. Institute of Physics, University of Muenster, Muenster 48149, Germany

    • Wolfram H. P. Pernice

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Contributions

All authors contributed substantially. W.H.P.P. and H.B. conceived, planned and supervised the project. C.R. and M.S. fabricated the samples and realized the reversible switching and multilevel measurements, and the thermo-optical response and speed measurements. P.H., C.D.W. and H.B. deposited and characterized the GST. D.W. and T.S. performed the TEM analysis of the specimen. All authors analysed the data and helped write the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Harish Bhaskaran or Wolfram H. P. Pernice.

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DOI

https://doi.org/10.1038/nphoton.2015.182

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