发表机构
Chungbuk National University（忠北国立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究证明经典光替代有损高斯玻色采样的平方根极限，并通过检测近似方法将平均幸存光子数提升至N^{2/3}，对构造达N^{3/4}。
AI 中文摘要
光子损失使得高斯玻色采样更容易被经典模拟。一种标准方法是用经典光替代有损输入，在固定压缩度和精度下，当幸存光子的平均数增长不超过N个压缩输入数量N的平方根时，该方法保持准确。我们证明这一尺度是经典光替代的极限。对于显式干涉仪，任何具有非负Glauber–Sudarshan P表示的态，无论高斯与否且无论多么相关，都不能在此尺度之上保持光子计数分布误差较小。我们随后通过近似检测而非输入来超越此极限。采样器在检测之间精确演化态，并在每次检测后，用具有相同协方差的高斯态替代条件态。对于每个干涉仪，其全变差误差为O(Nη^3)，期望成本为多项式级，其中η是光子存活概率。因此，平均幸存光子数可以在固定精度下增长为N^{2/3}。当每个输入模式被等量压缩时，一个单独的对构造达到N^{3/4}。
英文摘要
Photon loss makes Gaussian boson sampling easier to simulate classically. A standard approach replaces the lossy input by classical light, and it stays accurate while the mean number of surviving photons grows no faster than the square root of the number $N$ of squeezed inputs at fixed squeezing and accuracy. We prove that this scale is a limit of replacement by classical light. For explicit interferometers, no state with a nonnegative Glauber--Sudarshan $P$ representation, Gaussian or not and however correlated, keeps the error in the photon count distribution small beyond this scale. We then surpass this limit by approximating the detection instead of the input. The sampler evolves the state exactly between detections and, after each detection, replaces the conditional state by a Gaussian with the same covariance. For every interferometer its total variation error is $O(Nη^3)$ at polynomial expected cost, where $η$ is the photon survival probability. The mean surviving photon number can therefore grow as $N^{2/3}$ at fixed accuracy. A separate pair construction reaches $N^{3/4}$ when every input mode is equally squeezed.
Comments6+12 pages, 2 figures
