论文标题
GHz状态作为参考框架对齐的近乎最佳状态
GHZ states as near-optimal states for reference frame alignment
论文作者
论文摘要
让两个坐标系统拥有爱丽丝和鲍勃，通过so（3）$中的未知旋转$ r \相互关联。爱丽丝将向鲍勃发送同一状态$ |ψ_0\ ra $，后者将对接收的状态进行测量，并将确定旋转$ r $。鲍勃的任务是通过最佳测量值估算旋转$ r $的这些参数。根据量子渔民的信息，我们表明格林伯格 - 霍恩格林格（GHz）状态几乎是该任务的最佳状态。与以前提出的最佳状态相比，$ GHz $状态的优势是，它们可以更轻松地在实验上准备，更重要的是，我们显示的具体测量值将使鲍勃能够确定旋转$ r $。我们还研究了这些国家在噪音中保持其编码信息的鲁棒性。
Let two coordinate systems, in possession of Alice and Bob, be related to each other by an unknown rotation $R\in SO(3)$. Alice is to send identical states $|ψ_0\ra$ to Bob who will make measurements on the received state and will determine the rotation $R$. The task of Bob is to estimate these parameters of the rotation $R$ by the best possible measurements. Based on the Quantum Fisher Information, we show that Greenberger-Horne-Zeilinger (GHZ) states are near optimal states for this task. Compared to the optimal states proposed before, the advantage of $GHZ$ states are that they can be more easily prepared experimentally, and more importantly, we show concrete measurements which will allow Bob to determine the rotation $R$. We also study the robustness of these states in keeping their encoded information, against common sources of noises.
