论文标题
并非所有纠缠状态对于Ancilla辅助量子层析成像有用
Not all entangled states are useful for ancilla-assisted quantum process tomography
论文作者
论文摘要
众所周知，人们可以通过量子过程层析成像来提取未知量子通道的所有信息，例如标准的量子过程层析成像和辅助辅助量子过程断层扫描（AAQPT）。此外，已经表明，对于AAQPT而言，纠缠不是必需的，存在可分离的状态，也对其有用。令人惊讶的是，在这项工作中，我们发现并非所有纠缠状态都对AAQPT有用，也存在一些无用的纠缠状态。纠缠检测中使用的重新调整操作可能与问题有关，问题是否对AAQPT有用。我们得出它们之间的关系，并通过重组操作来显示未知通道的完整信息的过程。基于这种关系，我们介绍了两个Qutrit纠缠状态和两Qutrit绑定纠缠状态的例子。这两个示例都是纠缠的，但不能用于AAQPT。最后但并非最不重要的一点是，在IBM平台上也进行了实验验证。
It is well known that one can extract all the information of an unknown quantum channel by means of quantum process tomography, such as standard quantum-process tomography and ancilla-assisted quantum process tomography (AAQPT). Furthermore, it has been shown that entanglement is not necessary for AAQPT, there exist separable states which are also useful for it. Surprisingly, in this work we find that not all entangled states are useful for AAQPT, there also exist some entangled states which are useless. The realignment operation used in entanglement detection can be related to the question whether a bipartite state is useful for AAQPT. We derive the relationship between them and show the process of extracting the complete information of an unknown channel by the realignment operation. Based on this relationship, we present examples of a two-qutrit entangled state and a two-qutrit bound entangled state. Both of these two examples are entangled but they cannot be used for AAQPT. Last but not least, experimental verification has also been performed on the IBM platform.
