|| Entanglement-assisted multiple-access channels: capacity regions and protocol designs
||Haowei Shi, University of Arizona, United States; Min-Hsiu Hsieh, Hon Hai Research Institute, Taiwan; Saikat Guha, Zheshen Zhang, Quntao Zhuang, University of Arizona, United States|
||D1-S6-T4: Quantum Multiple Access Channels I
||Monday, 12 July, 23:40 - 00:00
||Tuesday, 13 July, 00:00 - 00:20
We solve the entanglement-assisted (EA) classical capacity region of quantum multiple-access channels with an arbitrary number of senders, which is conjectured by Hsieh, Devetak and Winter. As an example, we consider the bosonic thermal-loss multiple-access channel and solve the rate region enabled by an entanglement source composed of sender-receiver pairwise two-mode squeezed vacuum states. The EA rate region is strictly larger than the capacity region without entanglement-assistance, therefore also larger than the Yen-Shapiro rate-region of Gaussian encoding or coherent-state encoding. When the senders have equal low brightness, we also numerically find that the two-mode squeezed vacuum source is optimal at a corner rate point. With two-mode squeezed vacuum states as the source and phase modulation as the encoding, we also design practical receiver protocols to realize the entanglement advantages. In the parameter region of a large noise background, the receivers can enable a simultaneous rate advantage of 82.0% for each sender with binary phase-shift keying. Due to teleportation and superdense coding, our results for EA classical communication can be directly extended to EA quantum communication at half of the rates.