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Ultra-large-scale continuous-variable cluster states multiplexed in the time domain

Abstract

Quantum computers promise ultrafast performance for certain tasks1. Experimentally appealing, measurement-based quantum computation2 requires an entangled resource called a cluster state3, with long computations requiring large cluster states. Previously, the largest cluster state consisted of eight photonic qubits4 or light modes5, and the largest multipartite entangled state of any sort involved 14 trapped ions6. These implementations involve quantum entities separated in space and, in general, each experimental apparatus is used only once. Here, we circumvent this inherent inefficiency by multiplexing light modes in the time domain. We deterministically generate and fully characterize a continuous-variable cluster state7,8 containing more than 10,000 entangled modes. This is, by three orders of magnitude, the largest entangled state created to date. The entangled modes are individually addressable wave packets of light in two beams. Furthermore, we present an efficient scheme for measurement-based quantum computation on this cluster state based on sequential applications of quantum teleportation.

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Figure 1: Schematic of the experimental set-up and ultra-large-scale XEPR state.
Figure 2: XEPR states for sequential quantum teleportation.
Figure 3: Measured quantum correlations of the first fifty wave packets.
Figure 4: Quantum correlations of the XEPR state for the first 30,000 wave packets.

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References

  1. Nielsen, M. A. & Chuang, I. L. Quantum Computation and Quantum Information (Cambridge Univ. Press, 2000).

    MATH  Google Scholar 

  2. Raussendorf, R. & Briegel, H. J. A one-way quantum computer. Phys. Rev. Lett. 86, 5188–5191 (2001).

    Article  ADS  Google Scholar 

  3. Briegel, H. J. & Raussendorf, R. Persistent entanglement in arrays of interacting particles. Phys. Rev. Lett. 86, 910–913 (2001).

    Article  ADS  Google Scholar 

  4. Yao, X.-C. et al. Observation of eight-photon entanglement. Nature Photon. 6, 225–228 (2012).

    Article  ADS  Google Scholar 

  5. Su, X. et al. Experimental preparation of eight-partite cluster state for photonic qumodes. Opt. Lett. 37, 5178–5180 (2012).

    Article  ADS  Google Scholar 

  6. Monz, T. et al. 14-Qubit entanglement: creation and coherence. Phys. Rev. Lett. 106, 130506 (2011).

    Article  ADS  Google Scholar 

  7. Zhang, J. & Braunstein, S. L. Continuous-variable Gaussian analog of cluster states. Phys. Rev. A 73, 032318 (2006).

    Article  ADS  Google Scholar 

  8. Menicucci, N. C. et al. Universal quantum computation with continuous-variable cluster states. Phys. Rev. Lett. 97, 110501 (2006).

    Article  ADS  Google Scholar 

  9. Einstein, A., Podolsky, B. & Rosen, N. Can quantum-mechanical description of physical reality be considered complete? Phys. Rev. 47, 777–780 (1935).

    Article  ADS  Google Scholar 

  10. Bell, J. S. On the Einstein–Podolsky–Rosen paradox. Physics 1, 195–200 (1964).

    Article  MathSciNet  Google Scholar 

  11. Furusawa, A. & van Loock, P. Quantum Teleportation and Entanglement (Wiley-VCH, 2011).

    Chapter  Google Scholar 

  12. Bennett, C. H. et al. Teleporting an unknown quantum state via dual classical and Einstein–Podolsky–Rosen channels. Phys. Rev. Lett. 70, 1895–1899 (1993).

    Article  ADS  MathSciNet  Google Scholar 

  13. Furusawa, A. et al. Unconditional quantum teleportation. Science 282, 706–709 (1998).

    Article  ADS  Google Scholar 

  14. Lee, N. et al. Teleportation of nonclassical wave packets of light. Science 332, 330–333 (2011).

    Article  ADS  Google Scholar 

  15. Walther, P. et al. Experimental one-way quantum computing. Nature 434, 169–176 (2005).

    Article  ADS  Google Scholar 

  16. Tokunaga, Y. et al. Generation of high-fidelity four-photon cluster state and quantum-domain demonstration of one-way quantum computing. Phys. Rev. Lett. 100, 210501 (2008).

    Article  ADS  Google Scholar 

  17. Ukai, R. et al. Demonstration of unconditional one-way quantum computations for continuous variables. Phys. Rev. Lett. 106, 240504 (2011).

    Article  ADS  Google Scholar 

  18. Ukai, R., Yokoyama, S., Yoshikawa, J., van Loock, P. & Furusawa, A. Demonstration of a controlled-phase gate for continuous-variable one-way quantum computation. Phys. Rev. Lett. 107, 250501 (2011).

    Article  ADS  Google Scholar 

  19. Yukawa, M., Ukai, R., van Loock, P. & Furusawa, A. Experimental generation of four-mode continuous-variable cluster states. Phys. Rev. A 78, 012301 (2008).

    Article  ADS  Google Scholar 

  20. Van Loock, P., Weedbrook, C. & Gu, M. Building Gaussian cluster states by linear optics. Phys. Rev. A 76, 032321 (2007).

    Article  ADS  Google Scholar 

  21. Armstrong, S. et al. Programmable multimode quantum networks. Nature Commun. 3, 1026 (2012).

    Article  ADS  Google Scholar 

  22. Pysher, M., Miwa, Y., Shahrokhshahi, R., Bloomer, R. & Pfister, O. Parallel generation of quadripartite cluster entanglement in the optical frequency comb. Phys. Rev. Lett. 107, 030505 (2011).

    Article  ADS  Google Scholar 

  23. Roslund, J., de Araújo, R. M., Jiang, S., Fabre, C. & Treps, N. Wavelength-multiplexed quantum network with ultrafast frequency combs. Preprint at http://lanl.arXiv.org/abs/1307.1216 (2013).

  24. Menicucci, N. C., Flammia, S. T. & Pfister, O. One-way quantum computing in the optical frequency comb. Phys. Rev. Lett. 101, 130501 (2008).

    Article  ADS  Google Scholar 

  25. Menicucci, N. C. Temporal-mode continuous-variable cluster states using linear optics. Phys. Rev. A 83, 062314 (2011).

    Article  ADS  Google Scholar 

  26. Usmani, I., Afzelius, M., de Riedmatten, H. & Gisin, N. Mapping multiple photonic qubits into and out of one solid-state atomic ensemble. Nature Commun. 1, 12 (2010).

    Article  ADS  Google Scholar 

  27. Gu, M., Weedbrook, C., Menicucci, N. C., Ralph, T. C. & van Loock, P. Quantum computing with continuous-variable clusters. Phys. Rev. A 79, 062318 (2009).

    Article  ADS  Google Scholar 

  28. Menicucci, N. C., Flammia, S. T. & van Loock, P. Graphical calculus for Gaussian pure states. Phys. Rev. A 83, 042335 (2011).

    Article  ADS  Google Scholar 

  29. Van Loock, P. & Furusawa, A. Detecting genuine multipartite continuous-variable entanglement. Phys. Rev. A 67, 052315 (2003).

    Article  ADS  Google Scholar 

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Acknowledgements

This work was partly supported by the Project for Developing Innovation Systems (PDIS), Grants-in-Aid for Scientific Research (GIA), the Global Center of Excellence (G-COE) and the Advanced Photon Science Alliance (APSA) commissioned by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST) initiated by the Council for Science and Technology Policy (CSTP) of Japan, and the Australian Research Council (ARC) Centre of Excellence for Quantum Computation & Communication Technology (CQC2T; project number CE110001027). S.Y. acknowledges financial support from Advanced Leading Graduate Course for Photon Science (ALPS). R.U. acknowledges support from the Japan Society for the Promotion of Science (JSPS). S.A. acknowledges financial support from the Prime Minister's Australia Asia Award. N.C.M. was supported by the ARC (grant no. DE120102204).

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Contributions

S.Y., R.U. and S.A. planned and designed the experiment under the supervision of J.Y., H.Y. and A.F., based on the proposal by N.C.M. The experimental set-up were designed by S.Y., and the optical set-up was constructed by C.S., T.K. and S.Y. The fibre alignment system was built by S.S. The theory was formulated by R.U., S.A., N.C.M. and J.Y. R.U. designed and constructed the data acquisition system. S.A. designed and constructed the digital control system. R.U., S.A., T.K. and S.Y. conducted the data analysis. H.Y. assisted in noise analysis. S.Y. and S.A. wrote the manuscript with assistance from the team.

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Correspondence to Akira Furusawa.

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The authors declare no competing financial interests.

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Yokoyama, S., Ukai, R., Armstrong, S. et al. Ultra-large-scale continuous-variable cluster states multiplexed in the time domain. Nature Photon 7, 982–986 (2013). https://doi.org/10.1038/nphoton.2013.287

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