Capacity of trace decreasing quantum operations and superadditivity of coherent information for a generalized erasure channel
Capacity of trace decreasing quantum operations and superadditivity of coherent information for a generalized erasure channel
复制标题
广义擦除通道的痕量递减量子运算能力和相干信息超可加性
DOI：
--
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
S. Filippov
中科院分区：
文献类型：
--
作者：
S. Filippov
量子通信线路的损耗严重影响了可靠的信息传输速率，通常被认为是与状态无关的。然而，损耗概率通常依赖于系统状态，偏振相关损耗是一个突出的例子。在这里，我们分析了为态分配不同损失概率的有偏迹递减量子操作，并引入了广义擦除信道的概念。我们得到了广义擦除信道的经典容量和量子容量的上下界，并刻画了它的降解性和抗降解性。在偏振相关损耗的情况下，我们揭示了相干信息的超加性，两个字母的量子容量与单字母的量子容量之差超过7.197×10−3比特/量子比特，是迄今报道的量子比特输入通道中的最大值。
Losses in quantum communication lines severely affect the rates of reliable information transmission and are usually considered to be state-independent. However, the loss probability does depend on the system state in general, with the polarization dependent losses being a prominent example. Here we analyze biased trace decreasing quantum operations that assign different loss probabilities to states and introduce the concept of a generalized erasure channel. We find lower and upper bounds for the classical and quantum capacities of the generalized erasure channel as well as characterize its degradability and antidegradability. We reveal superadditivity of coherent information in the case of the polarization dependent losses, with the difference between the two-letter quantum capacity and the single-letter quantum capacity exceeding 7.197 × 10−3 bits per qubit sent, the greatest value among qubit-input channels reported so far.
影响因子：
2.9
作者：
Leditzky, Felix;Kaur, Eneet;Wilde, Mark M.
通讯作者：
Wilde, Mark M.