Abstract
Squeezing operation is critical for continuous-variable quantum information, enabling encoding of information in phase space to a resolution otherwise forbidden by vacuum noise1. A universal squeezing gate that can squeeze arbitrary input states is particularly essential for continuous-variable quantum computation2,3. However, the fidelity of existing state-of-the-art implementations is ultimately limited due to their reliance on first synthesizing squeezed vacuum modes of unbounded energy4,5. Here, we circumvent this fundamental limitation by using a heralded squeezing gate. This allows improved gate fidelity without requiring more squeezed ancillary vacuum. For a specific target squeezing level for coherent states, we present measured fidelities higher than what would be possible using non-heralded schemes that utilize up to 15 dB (ref. 6) of best available ancilla squeezing. Our technique can be applied to non-Gaussian states and provides a promising pathway towards high-fidelity gate operations and fault-tolerant continuous-variable quantum computation.
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Data availability
The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.
References
Weedbrook, C. et al. Gaussian quantum information. Rev. Mod. Phys. 84, 621 (2012).
Mile, G., Weedbrook, C., Menicucci, N. C., Ralph, T. C. & van Loock, P. Quantum computing with continuous-variable clusters. Phys. Rev. A 79, 062318 (2009).
Menicucci, N. C. Fault-tolerant measurement-based quantum computing with continuous-variable cluster states. Phys. Rev. Lett. 112, 120504 (2014).
Miyata, K. et al. Experimental realization of a dynamic squeezing gate. Phys. Rev. A 90, 060302 (2014).
Ukai, R. et al. Demonstration of unconditional one-way quantum computations for continuous variables. Phys. Rev. Lett. 106, 240504 (2011).
Vahlbruch, H., Mehmet, M., Danzmann, K. & Schnabel, R. Detection of 15 dB squeezed states of light and their application for the absolute calibration of photoelectric quantum efficiency. Phys. Rev. Lett. 117, 110801 (2016).
Menicucci, N. C., Ma, X. & Ralph, T. C. Arbitrarily large continuous-variable cluster states from a single quantum nondemolition gate. Phys. Rev. Lett. 104, 250503 (2010).
Braustein, S. L. Squeezing as an irreducible resource. Phys. Rev. A 71, 055801 (2005).
Yurke, B. Optical back-action-evading amplifiers. J. Opt. Soc. Am. B 2, 732–738 (1985).
Yoshikawa, J.-I. et al. Demonstration of a quantum nondemolition sum gate. Phys. Rev. Lett. 101, 250501 (2008).
Puri, S. & Blais, A. High-fidelity resonator-induced phase gate with single-mode squeezing. Phys. Rev. Lett. 116, 180501 (2016).
Braustein, S. L. Error correction for continuous quantum variables. Phys. Rev. Lett. 80, 4084–4087 (1998).
LeJeannic, H., Cavailles, A., Huang, K., Filip, R. & Laurat, J. Slowing quantum decoherence by squeezing in phase space. Phys. Rev. Lett. 120, 073603 (2018).
Miwa, Y. et al. Exploring a new regime for processing optical qubits: squeezing and unsqueezing single photons. Phys. Rev. Lett. 113, 013601 (2014).
Takeoka, M. & Sasaki, M. Discrimination of the binary coherent signal: Gaussian-operation limit and simple non-Gaussian near-optimal receivers. Phys. Rev. A 78, 022320 (2008).
Andersen, U. L., Gehring, T., Marquardt, C. & Leuchs, G. 30 years of squeezed light generation. Phys. Scr. 91, 053001 (2016).
Yoshikawa, J.-I. et al. Demonstration of deterministic and high fidelity squeezing of quantum information. Phys. Rev. A 76, 060301 (2007).
Su, X. et al. Gate sequence for continuous variable one-way quantum computation. Nat. Commun. 4, 2828 (2013).
de Oliveira, F. A. M. & Knight, P. L. Bright squeezing. Phys. Rev. Lett. 61, 830–833 (1988).
LaPorta, A., Slusher, R. E. & Yurke, B. Back-action evading measurements of an optical field using parametric down conversion. Phys. Rev. Lett. 62, 28–31 (1989).
Zhang, J., Ye, C., Gao, F. & Xiao, M. Phase-sensitive manipulations of a squeezed vacuum field in an optical parametric amplifier inside an optical cavity. Phys. Rev. Lett. 101, 233602 (2008).
Ma, H., Ye, C., Wei, D. & Zhang, J. Coherence phenomena in the phase-sensitive optical parametric amplification inside a cavity. Phys. Rev. Lett. 95, 233601 (2005).
Fiurášek, J. & Cerf, N. J. Gaussian postselection and virtual noiseless amplification in continuous-variable quantum key distribution. Phys. Rev. A 86, 060302 (2012).
Chrzanowski, H. M. et al. Measurement-based noiseless linear amplification for quantum communication. Nat. Photon. 8, 333–338 (2014).
Zhao, J., Hao, J. Y., Symul, T., Lam, P. K. & Assad, S. M. Characterization of a measurement-based noiseless linear amplifier and its applications. Phys. Rev. A 96, 012319 (2017).
Laurat, J., Coudreau, T., Treps, N., Matre, A. & Fabre, C. Conditional preparation of a quantum state in the continuous variable regime: generation of a sub-Poissonian state from twin beams. Phys. Rev. Lett. 91, 213601 (2003).
Andersen, U. L., Neergaard-Nielsen, J. S., van Loock, P. & Furusawa, A. Hybrid discrete- and continuous-variable quantum information. Nat. Phys. 11, 713–719 (2015).
van Loock, P. Optical hybrid approaches to quantum information. Laser Photon. Rev. 5, 167–200 (2011).
Ralph, T. C. Coherent superposition states as quantum rulers. Phys. Rev. A 65, 042313 (2002).
Munro, W. J., Nemoto, K., Milburn, G. J. & Braustein, S. L. Weak-force detection with superposed coherent states. Phys. Rev. A 66, 023819 (2002).
Menicucci, N. C. et al. Universal quantum computation with continuous-variable cluster states. Phys. Rev. Lett. 97, 110501 (2006).
Taylor, M. A. et al. Biological measurement beyond the quantum limit. Nat. Photon. 7, 229–233 (2013).
Bash, B. A., Gagatsos, C. N., Datta, A. & Guha, S. Fundamental limits of quantum-secure covert optical sensing. In Proc. 2017 IEEE Int. Symp. on Information Theory 3210–3214 (IEEE, 2017).
Acknowledgements
The research is supported by the Australian Research Council (ARC) under the Centre of Excellence for Quantum Computation and Communication Technology (CE110001027). K.L. is supported by the National Natural Science Foundation of China (grants 11674205 and 91536222). M.G. acknowledges funding from The National Research Foundation of Singapore (NRF Fellowship reference no. NRF-NRFF2016-02) and the Singapore Ministry of Education Tier 1 RG190/17. M.G. thanks the Institute of Advanced Study at NTU for funding the travel that catalysed this work. P.K.L. is an ARC Laureate Fellow.
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S.M.A., J.Z., M.G., J.T. and P.K.L. conceived the experiment. S.M.A. and J.Z. developed the theoretical model. J.Z., K.L., H.J., S.M.A. and P.K.L. planned and performed the experiment. J.Z. and S.M.A. analysed the data. J.Z., S.M.A., H.J., J.T., M.G. and P.K.L. drafted the initial manuscript. All authors discussed the results and commented on the manuscript.
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The Supplementary Information includes seven sections, Supplementary Figs. 1–7 and Supplementary Table 1.
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Zhao, J., Liu, K., Jeng, H. et al. A high-fidelity heralded quantum squeezing gate. Nat. Photonics 14, 306–309 (2020). https://doi.org/10.1038/s41566-020-0592-2
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DOI: https://doi.org/10.1038/s41566-020-0592-2
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