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arXiv 2402.04404quant-ph
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相空间中高斯函数线性组合的正交相干尺度

Quadrature Coherence Scale of Linear Combinations of Gaussian Functions in Phase Space

Anaelle Hertz, Aaron Z. Goldberg, Khabat Heshami

AI总结:

本文提出计算 Wigner 函数为高斯函数线性组合的量子态正交相干尺度的方法,并用于分析损耗下非经典性的可扩展性及培育协议输出态质量。

摘要:

正交相干尺度(QCS)是最近引入的一种度量,已被证明是非经典性的有效见证。对于纯态和高斯态,它形式简单,但对于混合态的一般表达式往往过于繁重而难以使用。在本文中,我们提出了一种计算量子态正交相干尺度的方法,这些量子态的 Wigner 函数可表示为高斯函数的线性组合。该框架下的显著例子包括猫态、GKP 态,以及由高斯变换、测量和培育协议产生的态。特别地,我们证明了正交相干尺度是考察存在损耗时非经典性可扩展性的重要工具。我们的发现使我们提出一个猜想:在 50% 或更多损耗条件下,所有纯态都会失去任何可由 QCS 认证的非经典性。我们还将正交相干尺度视为衡量培育协议输出态质量的一种度量。

英文摘要:

The quadrature coherence scale (QCS) is a recently introduced measure that was shown to be an efficient witness of nonclassicality. It takes a simple form for pure and Gaussian states, but a general expression for mixed states tends to be prohibitively unwieldy. In this paper, we introduce a method for computing the quadrature coherence scale of quantum states characterized by Wigner functions expressible as linear combinations of Gaussian functions. Notable examples within this framework include cat states, GKP states, and states resulting from Gaussian transformations, measurements, and breeding protocols. In particular, we show that the quadrature coherence scale serves as a valuable tool for examining the scalability of nonclassicality in the presence of loss. Our findings lead us to put forth a conjecture suggesting that, subject to 50% loss or more, all pure states lose any QCS-certifiable nonclassicality. We also consider the quadrature coherence scale as a measure of quality of the output state of the breeding protocol.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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