论文标题
远程准备光学schrödinger猫状态通过非同型三个photon自发下调中的同伴检测
Remotely preparing optical Schrödinger cat states via homodyne detection in nondegenerate triple-photon spontaneous downconversion
论文作者
论文摘要
光学下调是生成非经典状态的关键资源。最近，在超导装置（2020Phys。X10 011011）中已证明了具有明亮的光子三重态和强烈的三阶相关性的直接非平衡三光子自发下调（NTPSD）。此外，在此过程中还预测了线性和非线性三方纠缠（2018Phys。Rev.Lett。120043601; 2020Phys。Phys。Rev.Lett。125020502）。在本文中，我们考虑了非经典光学量子叠加的产生，并研究了NTPSD中的非线性量子转向效应。我们发现，当其他两种模式受到同源性检测时，可以实现一种大小的schrödinger猫状态。同样，只有一种模式被赋予一个模式，就可以生成一个两光钟纠缠的状态。我们进一步揭示了远程转向的这种能力源自三胞胎之间的非线性量子量子可触及的相关性。这是由于似乎违反了海森堡的不确定性关系的侵犯，这是基于另一种模式的同个模式的结果，即非线性量子转向的结果，与原始EPR旋转相比，基于其他模式的结果，基于其他模式的结果的推断差异。我们的结果表明，NTPSD中非高斯非古典特征，对于量子物理学和光学量子技术的实现非常有用。
Optical downconversion is a key resource for generating nonclassical states. Very recently, direct nondegenerate triple-photon spontaneous downconversion (NTPSD) with bright photon triplets and strong third-order correlations has been demonstrated in a superconducting device (2020 Phys. Rev. X 10 011011). Besides, linear and nonlinear tripartite entanglement in this process have also been predicted (2018 Phys. Rev. Lett. 120 043601; 2020 Phys. Rev. Lett. 125 020502). In this paper, we consider the generation of nonclassical optical quantum superpositions and investigate nonlinear quantum steering effects in NTPSD.We find that large-size Schrödinger cat states of one downconverted mode can be achieved when the other two modes are subjected to homodyne detection. Also, a two-photon Bell entangled state can be generated when only one mode is homodyned.We further reveal that such ability of remote state steering originates from nonlinear quantum steerable correlations among the triplets. This is specifically embodied by the seeming violation of the Heisenberg uncertainty relation for the inferred variances of two noncommutating higher-order quadratures of downconverted modes, based on the outcomes of homodyne detection on the other mode, i.e., nonlinear quantum steering, compared to original EPR steering. Our results demonstrate non-Gaussian nonclassical features in NTPSD and would be useful for the fundamental tests of quantum physics and implementations of optical quantum technologies.
