NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
NTT Research Center for Theoretical Quantum Physics, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
Phys Rev Lett. 2018 Dec 21;121(25):250504. doi: 10.1103/PhysRevLett.121.250504.
Bipartite quantum interactions have applications in a number of different areas of quantum physics, reaching from fundamental areas such as quantum thermodynamics and the theory of quantum measurements to other applications such as quantum computers, quantum key distribution, and other information processing protocols. A particular aspect of the study of bipartite interactions is concerned with the entanglement that can be created from such interactions. In this Letter, we present our work on two basic building blocks of bipartite quantum protocols, namely, the generation of maximally entangled states and secret key via bipartite quantum interactions. In particular, we provide a nontrivial, efficiently computable upper bound on the positive-partial-transpose-assisted quantum capacity of a bipartite quantum interaction. In addition, we provide an upper bound on the secret-key-agreement capacity of a bipartite quantum interaction assisted by local operations and classical communication. As an application, we introduce a cryptographic protocol for the readout of a digital memory device that is secure against a passive eavesdropper.
双量子相互作用在量子物理学的许多不同领域都有应用，从量子热力学和量子测量理论等基础领域到量子计算机、量子密钥分发和其他信息处理协议等其他应用。双量子相互作用研究的一个特定方面涉及可以从这种相互作用中产生的纠缠。在这封信中，我们介绍了我们在双量子协议的两个基本构建块方面的工作，即通过双量子相互作用生成最大纠缠态和秘密密钥。特别是，我们提供了一个非平凡的、可有效计算的双量子相互作用的正部分转置辅助量子容量的上界。此外，我们还提供了在本地操作和经典通信辅助下的双量子相互作用的秘密密钥协商容量的上界。作为应用，我们引入了一种针对数字存储设备读取的加密协议，该协议可防止被动窃听者的攻击。
