Experimental Demonstration of Quantum Steering Swapping with Gaussian Entangled States

• Published in: Laser & photonics reviews Vol. 18; no. 1
• Main Authors: Wang, Na, Wang, Meihong, Tian, Caixing, Deng, Xiaowei, Su, Xiaolong
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.01.2024
• Subjects: Data processing; entangled state; Entangled states; Quantum cryptography; Quantum entanglement; Quantum phenomena; quantum steering; quantum teleportation; squeezed state; Steering
• ISSN: 1863-8880; 1863-8899
• DOI: 10.1002/lpor.202300653

As a key element in quantum repeaters, entanglement swapping establishes entanglement between two independent entangled states. Besides entanglement, quantum steering has been identified as an essential quantum resource and has broad applications in quantum communication. Although entanglement swapping has been realized experimentally, quantum steering swapping still remains a challenge since the condition of quantum steering is stronger than that of entanglement. In this article, quantum steering swapping between a three‐mode and a two‐mode Gaussian entangled state in a lossy channel is demonstrated. By choosing the optimum gain in the classical channel that corresponds to the maximum transmission distance, the one‐way and two‐way steerabilities in a new three‐mode Gaussian state located in distant nodes are achieved. The obtained collective steerability from two users to one user has potential application in quantum secret sharing. The results make a crucial step toward applications of quantum steering in asymmetric quantum information processing. Quantum steering swapping of Gaussian entangled states in a lossy channel is experimentally demonstrated. By choosing the optimum gains in classical channels, the one‐way and two‐way steerabilities of a new three‐mode Gaussian state located in distant nodes are obtained. This work provides a feasible method to establish quantum steering between two space‐separated independent Gaussian states without direct interaction.