Port-based teleportation (PBT) is a teleportation protocol that employs a number of Bell pairs and a joint measurement to enact an approximate input-output identity channel. Replacing the Bell pairs with a different multi-qubit resource state changes the enacted channel and allows the PBT protocol to simulate qubit channels beyond the identity. The channel resulting from PBT using a general resource state is consequently of interest. In this work, we fully characterise the Choi matrix of the qubit channel simulated by the PBT protocol in terms of its resource state. We also characterise the PBT protocol itself, by finding a description of the map from the resource state to the Choi matrix of the channel that is simulated by using that resource state. Finally, we exploit our expressions to show improved simulations of the amplitude damping channel by means of PBT with a finite number of ports.

基于端口的传送 (PBT) 是一种传送协议，它采用多个贝尔对和联合测量来制定近似的输入输出身份通道。用不同的多量子位资源状态替换贝尔对会改变已制定的通道，并允许 PBT 协议模拟超越身份的量子位通道。因此，使用通用资源状态的 PBT 产生的信道是令人感兴趣的。在这项工作中，我们根据资源状态充分表征了 PBT 协议模拟的量子比特通道的 Choi 矩阵。我们还通过找到从资源状态到使用该资源状态模拟的信道的 Choi 矩阵的映射的描述来表征 PBT 协议本身。最后，