论文标题
在不平衡干涉仪中最大化量子渔民信息
Quantum Fisher information maximization in an unbalanced interferometer
论文作者
论文摘要
在本文中，我们提供了以下问题的答案：鉴于任意的纯输入状态和一般，不平衡，马赫德尔干涉仪，第一光束的传输系数是什么传输系数splitter最大化量子渔民信息（QFI）？我们考虑了单参数QFI和换句话说，无论是否访问外部阶段参考，我们都会考虑这个问题。我们为所有相关场景提供分析结果。事实证明，对于大量的输入状态，平衡（50/50）方案产生了最佳的两参数QFI，但这远非普遍的真理。当涉及单参数QFI时，平衡场景很少是最佳的场景，而不平衡的干涉仪可以比平衡案例带来显着优势。我们还陈述了对输入状态的条件，因此无法通过外部相参考来利用计量学的优势。最后，我们通过许多示例（包括高斯和非高斯输入状态）来说明和讨论我们的断言。
In this paper we provide the answer to the following question: given an arbitrary pure input state and a general, unbalanced, Mach-Zehnder interferometer, what transmission coefficient of the first beam splitter maximizes the quantum Fisher information (QFI)? We consider this question for both single- and two-parameter QFI, or, in other words, with or without having access to an external phase reference. We give analytical results for all involved scenarios. It turns out that, for a large class of input states, the balanced (50/50) scenario yields the optimal two-parameter QFI, however this is far from being a universal truth. When it comes to the single-parameter QFI, the balanced scenario is rarely the optimal one and an unbalanced interferometer can bring a significant advantage over the balanced case. We also state the condition imposed upon the input state so that no metrological advantage can be exploited via an external phase reference. Finally, we illustrate and discuss our assertions through a number of examples, including both Gaussian and non-Gaussian input states.
