2016/06/07 by Lirong Chen, Chen, Lirong, Zhongxiao Xu +9
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #Quantum optics and atomic interactions
paper · pdf · doi:10.48550/arxiv.1606.02123
openalex publication_date 2016/06/07 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report an experiment in which long-lived quantum memories for photonic polarization qubits (PPQs) are controllably released into any one of multiple separate channels. The PPQs are implemented with an arbitrarily-polarized coherent signal light pulses at the single-photon level and are stored in cold atoms by means of electromagnetic-induced-transparency scheme. Reading laser pulses propagating along the direction at a small angle relative to quantum axis are applied to release the stored PPQs into an output channel. By changing the propagating directions of the read laser beam, we controllably release the retrieved PPQs into 7 different photonic output channels, respectively. At one of the output channels, the measured maximum quantum-process fidelity for the PPQs is 94.2% at storage time of t= 0.85ms. At storage time of 6 ms, the quantum-process fidelity is still beyond 78%, the threshold for the violation of the Bell inequality. The demonstrated controllable release of the stored PPQs may extend the capabilities of the quantum information storage technique.