Nonlinear Squeezing for Measurement-Based Non-Gaussian Operations in Time Domain
Nonlinear Squeezing for Measurement-Based Non-Gaussian Operations in Time Domain
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DOI：
10.1103/physrevapplied.15.024024
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发表时间：
2021-02-10
影响因子：
4.6
通讯作者：
Furusawa, Akira
中科院分区：
文献类型：
--
作者：
Konno, Shunya;Sakaguchi, Atsushi;Furusawa, Akira
量子非高斯门是光学系统中实现连续变通用量子运算的缺失部分。在基于测量的三次相门实现中，需要具有非线性压缩特性的最低阶非高斯门和非高斯辅助态。然而，这种性质从未被实验证实过。本文在真空态和单光子态之间建立了一个叠加态，通过优化叠加系数使其非线性压缩最大化。通过实时正交测量观察到非线性压缩，这意味着生成的状态与实时前馈兼容，并且适合作为时域三次相门的辅助状态。此外，通过增加光子数，有望进一步改善非线性压缩。本文提出的思想可以很容易地扩展到高阶相门[P]。马立克等人，物理学。中国农业科学，1997,022329 (2018)[j]。因此，这项工作为将连续变量量子信息处理从高斯域扩展到非高斯域迈出了重要的一步。
Quantum non-Gaussian gate is a missing piece to the realization of continuous-variable universal quantum operations in an optical system. In a measurement-based implementation of the cubic phase gate, a lowest-order non-Gaussian gate, non-Gaussian ancillary states that have a property we call nonlinear squeezing are required. This property, however, has never been experimentally verified. In this paper, we generate a superposition between a vacuum state and a single-photon state whose nonlinear squeezing is maximized by the optimization of the superposition coefficients. The nonlinear squeezing is observed via real-time quadrature measurements, meaning that the generated states are compatible with real-time feedforward and are suitable as ancillary states for the cubic phase gate in the time domain. Moreover, by increasing the number of photons, it is expected that nonlinear squeezing can be further improved. The idea presented here can be readily extended to higher-order phase gates [P. Marek et al., Phys. Rev. A 97, 022329 (2018)]. As such, this work presents an important step to extend continuous-variable quantum information processing from Gaussian regime to non-Gaussian regime.