Communication over a quantum multiple-access channel (MAC) with cribbing encoders is considered, whereby Transmitter 2 performs a measurement on a system that is entangled with Transmitter 1. Based on the no-cloning theorem, perfect cribbing is impossible. This leads to the introduction of a MAC model with noisy cribbing. In the causal and non-causal cribbing scenarios, Transmitter 2 performs the measurement before the input of Transmitter 1 is sent through the channel. Hence, Transmitter 2's cribbing may inflict a "state collapse" for Transmitter 1. Achievable regions are derived for each setting. Furthermore, a regularized capacity characterization is established for robust cribbing, i.e. when the cribbing system contains all the information of the channel input. Building on the analogy between the noisy cribbing model and the relay channel, a partial decode-forward region is derived for a quantum MAC with non-robust cribbing. For the classical-quantum MAC with cribbing encoders, the capacity region is determined with perfect cribbing of the classical input, and a cutset region is derived for noisy cribbing. In the special case of a classical-quantum MAC with a deterministic cribbing channel, the inner and outer bounds coincide.

翻译：本文研究了具有窃听编码器的量子多址信道通信问题，其中发射机2对与发射机1纠缠的系统进行测量。基于不可克隆定理，完美窃听是不可能的。这引出了带噪声窃听的多址信道模型。在因果与非因果窃听场景中，发射机2在发射机1的输入通过信道发送之前进行测量。因此，发射机2的窃听可能导致发射机1的"态坍缩"。本文推导了每种设置下的可达区域。此外，针对鲁棒窃听（即当窃听系统包含信道输入的全部信息时）建立了正则化容量表征。基于噪声窃听模型与中继信道之间的类比，推导了具有非鲁棒窃听的量子多址信道的部分解码转发区域。对于具有窃听编码器的经典-量子多址信道，在完美窃听经典输入的情况下确定了容量区域，并针对噪声窃听推导了割集区域。在具有确定性窃听信道的经典-量子多址信道特例中，内外界重合。