Recent work has noted that a space-sharing argument proves the tightness of the entropic quantum Singleton bounds, which was left open in the literature for various settings involving only-quantum messages, only-classical messages, or both classical and quantum messages. Focusing on the setting of entanglement-assisted classical coding (EACC), in this letter we first elaborate upon the space-sharing argument and the tight Singleton bound for this setting, and then establish a new tight entropic Singleton bound for EACC codes with entanglement assistance distributed across a subset of encoders when only local quantum operations are allowed at each encoder.

翻译：近期研究指出，空间共享论证证明了熵量子单例界的紧致性，该问题在文献中对于仅涉及量子消息、仅涉及经典消息或同时涉及经典与量子消息的多种设定中均悬而未决。聚焦于纠缠辅助经典编码（EACC）的设定，本文首先详细阐述了该设定下的空间共享论证与紧致单例界，随后针对纠缠辅助在编码器间部分分布且各编码器仅允许进行局域量子操作的情形，为EACC码建立了一个新的紧致熵单例界。