发表机构
University of Ibn Tofail; Abdus Salam International Centre for Theoretical Physics (ICTP); Institute for Research in Fundamental Sciences (IPM)（伊本·图费勒大学; 阿卜杜斯·萨拉姆理论物理国际中心; 基础科学研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究在SU(1,1)干涉仪中以增光子偶、奇相干态为输入资源，证实增光子操作可提升相位灵敏度、超越标准量子极限并趋近海森堡标度，且m增大时奇偶态性能差异减弱。
AI 中文摘要
我们研究在SU(1,1)干涉仪中，采用m个光子的增光子偶相干态与奇相干态作为非经典输入资源的相位估计问题。通过强度探测和误差传播方法评估相位灵敏度，同时利用量子费舍尔信息作为相关计量学量，从量子克拉美罗界确定最终精度极限。研究结果表明，增光子操作显著提升了相位灵敏度，增加了量子费舍尔信息，降低了量子克拉美罗界，相比对应的偶、奇相干态有明显改善。此外，可实现的灵敏度超过标准量子极限，且随增光子数m增大逐渐趋近海森堡标度。我们还发现，m个光子的增光子偶相干态相比奇相干态表现出适度优势，但随着m增大，这种差异逐渐减弱，说明增光子操作削弱了相干态初始奇偶性对干涉仪性能的决定作用。
英文摘要
We investigate phase estimation in an SU(1,1) interferometer employing $m$-photon-added even and odd coherent states as nonclassical input resources. The phase sensitivity is evaluated through intensity detection and the error propagation method, while the ultimate precision limit is determined from the quantum Cramér-Rao bound with the quantum Fisher information serving as the relevant metrological quantity. Our results demonstrate that photon addition significantly enhances the phase sensitivity, increases the quantum Fisher information, and reduces the quantum Cramér-Rao bound, leading to a clear improvement over the corresponding even and odd coherent states. Furthermore, the achievable sensitivity exceeds the standard quantum limit and gradually approaches the Heisenberg scaling with increasing photon-addition number. We also find that the $m$-photon-added even coherent states exhibit a modest advantage over their odd counterparts. As $m$ increases, however, this distinction becomes progressively weaker, suggesting that photon addition diminishes the role of the initial parity of the coherent state in determining the interferometric performance.
Comments10 pages, 8 figures
