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arXiv 2403.18890quant-ph
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高斯玻色采样中的平均 Rényi 纠缠熵

Average Rényi Entanglement Entropy in Gaussian Boson Sampling

Jason Youm, Joseph T. Iosue, Adam Ehrenberg, Yu-Xin Wang, Alexey V. Gorshkov

AI总结:

本文在高斯玻色采样框架中研究输出态的模式纠缠,推导了无穷多模式极限下由单模压缩真空态组成的输入态在相等压缩强度时的 Rényi-α 熵 Page 曲线公式,并计算方差证明其弱典型性。

摘要:

近年来,许多实验以展示相对于经典计算的量子优势为目标而开展。这些实验的一个流行框架是高斯玻色采样,其中二次光子输入态通过线性光学幺正变换进行干涉,随后在 Fock 基下进行测量。在本工作中,我们研究该框架中输出态在测量阶段之前的模式纠缠。具体而言,我们计算由各种 Rényi-α 熵度量的 Page 曲线,其中 Page 曲线描述了对所有线性光学幺正变换平均后两组划分的输出模式之间的纠缠。我们在无穷多模式数的渐近极限下,针对由具有相等压缩强度的单模压缩真空态组成的输入态,推导了 α=1(即 von Neumann 熵)的公式,并且更一般地推导了所有正整数 α 的公式。随后,我们分析了压缩强度较小和较大时的极限行为。在确定平均值之后,我们进一步显式计算了整数 α>1 的 Rényi-α 方差,并能够证明这些熵是弱典型的。

英文摘要:

Recently, many experiments have been conducted with the goal of demonstrating a quantum advantage over classical computation. One popular framework for these experiments is Gaussian Boson Sampling, where quadratic photonic input states are interfered via a linear optical unitary and subsequently measured in the Fock basis. In this work, we study the modal entanglement of the output states in this framework just before the measurement stage. Specifically, we compute Page curves as measured by various Rényi-$α$ entropies, where the Page curve describes the entanglement between two partitioned groups of output modes averaged over all linear optical unitaries. We derive these formulas for $α= 1$ (i.e. the von Neumann entropy), and, more generally, for all positive integer $α$, in the asymptotic limit of infinite number of modes and for input states that are composed of single-mode-squeezed-vacuum state with equal squeezing strength. We then analyze the limiting behaviors when the squeezing is small and large. Having determined the averages, we then explicitly calculate the Rényi-$α$ variance for integers $α> 1$, and we are able to show that these entropies are weakly typical.

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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