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arXiv 1708.08548quant-phcond-mat.stat-mechmath-phmath.MPphysics.optics
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相干态光的最佳安全量子隐形传态

Optimal secure quantum teleportation of coherent states of light

Pietro Liuzzo-Scorpo, Gerardo Adesso

摘要:

研究了相位空间中位移为高斯分布的相干态系综的量子隐形传态。最近,在[P. Liuzzo-Scorpo et al.,arXiv:1705.03017]:给定有限的纠缠和平均能量作为资源,在这样一个状态字母表的隐形传态中,平均可以达到的最大保真度是多少?在这里,我们考虑这个问题的一个变体,其中Einstein-Podolsky-Rosen转向被用作资源而不是普通的纠缠。我们通过高斯量子信道的空间内的优化提供了一个解决方案,这使得问题的直观可视化。我们首先表明,并不是所有的通道都可以访问有限程度的转向,然后证明,依赖于非对称双模高斯状态的实际计划,使一个达到最大的保真度在边界处与不可访问的区域。我们的研究结果提供了一个严格的定量评估的转向作为一种资源的安全量子隐形传态超越所谓的无克隆阈值。我们提出的方案可以很容易地实现实验由传统的Braunstein-Kimble连续变量隐形传态协议,涉及零差检测和校正位移与最佳调谐增益。这些协议可以集成为量子网络中的基本构建块,用于量子光学状态的可靠存储和传输。

英文摘要:

We investigate quantum teleportation of ensembles of coherent states of light with a Gaussian distributed displacement in phase space. Recently, the following general question has been addressed in [P. Liuzzo-Scorpo et al., arXiv:1705.03017]: Given a limited amount of entanglement and mean energy available as resources, what is the maximal fidelity that can be achieved on average in the teleportation of such an alphabet of states? Here, we consider a variation of this question, where Einstein-Podolsky-Rosen steering is used as a resource rather than plain entanglement. We provide a solution by means of an optimisation within the space of Gaussian quantum channels, which allows for an intuitive visualisation of the problem. We first show that not all channels are accessible with a finite degree of steering, and then prove that practical schemes relying on asymmetric two-mode Gaussian states enable one to reach the maximal fidelity at the border with the inaccessible region. Our results provide a rigorous quantitative assessment of steering as a resource for secure quantum teleportation beyond the so-called no-cloning threshold. The schemes we propose can be readily implemented experimentally by a conventional Braunstein-Kimble continuous variable teleportation protocol involving homodyne detections and corrective displacements with an optimally tuned gain. These protocols can be integrated as elementary building blocks in quantum networks, for reliable storage and transmission of quantum optical states.

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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