发表机构
Inter-University Centre for Astronomy and Astrophysics (IUCAA); Poornaprajna Institute of Scientific Research（天文与天体物理大学间中心; 普尔纳普拉贾科学研究学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文分析有限能量GKP态增强的SU(2)和SU(1,1)干涉仪，证明宽包络GKP态在损耗下优于压缩真空，但低光子数时压缩真空更优，并给出QFI估计方法。
AI 中文摘要
我们提出了Gottesman-Kitaev-Preskill（GKP）态增强的光学干涉测量案例，并对SU(2)和SU(1,1)干涉仪的相位灵敏度进行了详细分析。传统的量子增强SU(2)干涉仪在一个输入端口使用相干光，另一个输入端口使用压缩光，我们将其与使用相干光和GKP态的改进配置进行了比较。虽然已知压缩真空态是与相干态配对时的最优高斯资源输入模式，但我们证明，具有足够宽包络的有限能量GKP态在存在光学损耗的情况下也优于压缩真空注入。这可归因于GKP情况下多个压缩峰带来的增强鲁棒性。然而，由于降低平均光子数会减小GKP包络宽度，当与平均光子数相等或更低的GKP态相比时，压缩真空输入表现更好。我们还观察到，光学损耗倾向于削弱任一输入态的相对优势，因为两种态都渐近趋近于（未压缩的）真空态。我们的工作展示了有限能量GKP态在光学干涉测量中的直接应用，以及一种估计量子Fisher信息（QFI）的方法，并提出了使用非高斯资源与常规高斯态相比的相位估计程序。
英文摘要
We present the case of a Gottesman-Kitaev-Preskill (GKP) state-enhanced optical interferometry with detailed analysis of the phase sensitivity for both the SU(2) and SU(1,1) interferometers. The conventional quantum-enhanced SU(2) interferometer, employing coherent light at one input port and squeezed light at the other, is compared with a modified configuration using coherent light and a GKP state. While it is known that the squeezed vacuum state is the optimal Gaussian resource input mode when paired with the coherent state, we show that the finite-energy GKP state with sufficiently broad envelope outperforms the squeezed vacuum injection, irrespective of the presence of optical losses. This can be attributed to the enhanced robustness coming from the availability of multiple squeezed peaks in the GKP case. However, because lowering the mean photon number reduces the GKP envelope width, the squeezed vacuum input performs better when compared with a GKP state of equal or lower mean photon number. We also observe that optical losses tend to diminish the relative advantage of either input state, since both states approach the (unsqueezed) vacuum state asymptotically. Our work demonstrates the direct application of finite-energy GKP states in optical interferometry along with a methodology for estimating the quantum Fisher information (QFI) and presents a phase estimation procedure using non-Gaussian resources in comparison with conventional Gaussian states.
