Kim Hyeon-Jin, Jung Ji-Hyeok, Lee Kyung-Jun, Ra Young-Sik
Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.
Sci Adv. 2023 Oct 6;9(40):eadi5261. doi: 10.1126/sciadv.adi5261. Epub 2023 Oct 4.
Entanglement is a crucial quantum resource with broad applications in quantum information science. For harnessing entanglement in practice, it is a prerequisite to certify the entanglement of a given quantum state. However, the certification process itself destroys the entanglement, thereby precluding further exploitation of the entanglement. Resolving this conflict, here, we present a protocol that certifies the entanglement of a quantum state without complete destruction and then probabilistically recovers the original entanglement to provide useful entanglement for further quantum applications. We experimentally demonstrate this protocol in a photonic quantum system and highlight its usefulness for selecting high-quality entanglement from a realistic entanglement source. Moreover, our study reveals various trade-off relations among the physical quantities involved in the protocol. Our results show how entanglement certification can be made compatible with subsequent quantum applications and be beneficial to sort entanglement for better performance in quantum technologies.
纠缠是一种关键的量子资源，在量子信息科学中有着广泛的应用。为了在实际中利用纠缠，认证给定量子态的纠缠是一个先决条件。然而，认证过程本身会破坏纠缠，从而排除了对纠缠的进一步利用。为了解决这一冲突，我们在此提出一种协议，该协议可在不完全破坏的情况下认证量子态的纠缠，然后以概率方式恢复原始纠缠，为进一步的量子应用提供有用的纠缠。我们在一个光子量子系统中通过实验演示了该协议，并强调了其对于从实际纠缠源中选择高质量纠缠的有用性。此外，我们的研究揭示了该协议中所涉及物理量之间的各种权衡关系。我们的结果表明了纠缠认证如何能够与后续量子应用兼容，并有利于对纠缠进行分类以在量子技术中实现更好的性能。
