腔光力体系中量子引导非局域性的理论研究

In this proposal, we will at first consider how to achieve steady and robust Gaussian quantum steering between light field and low-frequency mechanical oscillators by cavity optomechanics in the unresolved-sideband regime. Based on this achieved optomechanical quantum steering, we will further consider the realization of two-mode Gaussian quantum steering between two remote low-frequency mechanical oscillators and multipartite cluster-state-type quantum steering correlations among multiple distant low-frequency mechanical oscillators. Besides the above Gaussian quantum steering, we will put forward schemes for generating non-Gaussian quantum steering by engineering appropriate nonlinear optomechanical interactions. Also，the investigation on the enhancement of the strength of quantum steering correlations via non-Gaussian operations of photon (phonon) addition or subtraction will be carried out. By analytically solving the master equations of initial non-Gaussian steerable states in noisy environments, we intend to exactly reveal the effects of local or nonlocal baths on the asymmetry of non-Gaussian steering and moreover the link between non-Gaussianity and quantum steering. Subsequently, we will study in detail the security improvement of continuous-variable (CV) quantum teleportation with non-Guassian quantum steering correlations. We will derive criteria characterizing CV temporal quantum steering， and utilize them to measure non-Markovianity and study the properties of temporal quantum steering in cavity optomechanical systems. The potential applications of CV Gaussian and non-Gaussian quantum steering in secure quantum networks, one-way CV quantum computation and ultrahigh precise measurements will be addressed. This proposal will promote the development of researches on CV quantum steering and quantum effects in cavity optomechanics.

本项目将研究如何在边带非辨析区域实现光场与低频机械振子间稳定且强的高斯量子引导，并基于此进一步实现空间远距离两个低频振子间的高斯量子引导和多个低频振子cluster态的多体量子引导；提出有效的方案以在非线性腔光力体系中产生光场、振子及二者间的非高斯量子引导；考虑通过加、减光(声)子非高斯操作来实现量子引导的增强；精确求解非高斯量子引导态在噪声环境中的演化，准确揭示不同类型的局域或非局域环境对非高斯量子引导的反对称性的影响，细致考察非高斯性与量子引导之间的联系；深入研究非高斯量子引导对连续变量量子隐形传态的安全性的提高；提出连续变量时域量子引导的量化判据并用来描述环境的非马尔科夫性，研究腔光力体系在非线性区域的时域量子引导的性质。探讨高斯和非高斯量子引导在安全的量子网络、单向的量子计算以及高精密测量等领域中的应用。本项目的完成将深化有关连续变量量子引导和腔光力学中量子现象的研究。

当前，如何在边带非辨析区域实现低频微机械振子的非经典态和基于连续测量与量子反馈实现振子量子态的调控是量子光学的前沿研究课题。本项目研究了：1) 解析证明了高斯纠缠交换（Entanglement swapping）中子系统的量子引导关联的存在是实现混合态高斯纠缠交换的充分且必要条件,并解释了这是因为量子纠缠交换过程中零差测量致使体系复合模形成条件的量子压缩，从而使得两个远距离的体系间形成纠缠；2) 揭示了连续驱动条件下腔光力体系中光-力间稳定的量子引导特性，发现腔内非简并参量下转换过程在平衡耗散条件无量子引导，仅耗散小的子系统可引导耗散大的子系统，而反之非亦然；此外，我们还发现了通过腔输出场滤波可实现稳定且强的光-力间量子引导，在此基础上我们考虑了利用腔输出滤波来实现边带非辨析区域中稳健的两体和多体机械振子的量子引导；3) 研究了基于连续量子测量和量子反馈的微机械振子量子态的调控，发现了测量反作用可将体系的稳定区域扩充至强耦合条件下蓝失谐区域并降低了腔场的噪声，从而在边带非辨析区域可以实现稳定且强的振动压缩、光-力间量子引导关联、以及光-磁子-声子间真正的三体量子引导关联；4) 提出了通过减光子操作分别实现微机械振子的单声子Fock态和大幅度的薛定谔猫态的可行方案，精确求解了热环境对所获振动非高斯态的非经典性质的影响。上述研究成果对实现宏观体系的非经典特性以及构建量子通讯网络具有研究价值。