用低于阈值的自锁相型II OPO产生大正交EPR纠缠
Experimental Generation of Large Quadrature EPR Entanglement with a Self-Phase-Locked Type II OPO Below Threshold
摘要：
本文从理论和实验上研究了阈值以下的第二类频率简并光参量振荡器的量子特性，该振荡器在腔内插入四分之一波片，使正交偏振的信号光场和闲频光场之间产生线性耦合。这个原始设备提供了一个很好的洞察一般性质的双模高斯状态，说明在协方差矩阵。本文报道了在依赖于平板角的非正交正交积分上双模压缩真空的实验产生。经过简单的运算，纠缠被最大化，并转化为标准形式，\textit{i.e.}量子相关和正交反相关。压缩方差的一半和低至$0.33 \pm 0.02$，远低于单位极限的不可分性，获得和纠缠的形成熵测量。
英文摘要：
We study theoretically and experimentally the quantum properties of a type II frequency degenerate optical parametric oscillator below threshold with a quarter-wave plate inserted inside the cavity which induces a linear coupling between the orthogonally polarized signal and idler fields. This original device provides a good insight into general properties of two-mode gaussian states, illustrated in terms of covariance matrix. We report on the experimental generation of two-mode squeezed vacuum on non-orthogonal quadratures depending on the plate angle. After a simple operation, the entanglement is maximized and put into standard form, \textit{i.e.} quantum correlations and anti-correlations on orthogonal quadratures. A half-sum of squeezed variances as low as $0.33 \pm 0.02$, well below the unit limit for inseparability, is obtained and the entanglement measured by the entropy of formation.
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。
