He Qiongyi, Rosales-Zárate Laura, Adesso Gerardo, Reid Margaret D
State Key Laboratory of Mesoscopic Physics, School of Physics, Peking University, Collaborative Innovation Center of Quantum Matter, Beijing 100871 China.
Centre for Quantum and Optical Science, Swinburne University of Technology, Melbourne 3122, Australia.
Phys Rev Lett. 2015 Oct 30;115(18):180502. doi: 10.1103/PhysRevLett.115.180502. Epub 2015 Oct 27.
We investigate the resources needed for secure teleportation of coherent states. We extend continuous variable teleportation to include quantum teleamplification protocols that allow nonunity classical gains and a preamplification or postattenuation of the coherent state. We show that, for arbitrary Gaussian protocols and a significant class of Gaussian resources, two-way steering is required to achieve a teleportation fidelity beyond the no-cloning threshold. This provides an operational connection between Gaussian steerability and secure teleportation. We present practical recipes suggesting that heralded noiseless preamplification may enable high-fidelity heralded teleportation, using minimally entangled yet steerable resources.
我们研究了相干态安全隐形传态所需的资源。我们扩展了连续变量隐形传态，以纳入量子远程放大协议，该协议允许非单位经典增益以及相干态的预放大或后衰减。我们表明，对于任意高斯协议和一大类高斯资源，需要双向操控才能实现超越不可克隆阈值的隐形传态保真度。这提供了高斯可操控性与安全隐形传态之间的操作联系。我们给出了实用方法，表明利用最少纠缠但可操控的资源，有预示的无噪声预放大可能实现高保真度的有预示隐形传态。
