大动量转移原子重力测量的探测-分辨率极限
Detection-resolution limits of large-momentum-transfer atom gravimetry
浏览论文内容
中文总结 AI 辅助
该研究分析大动量转移原子重力测量中，大动量转移增益与探测器分辨率的权衡，得出无镜操作超越常规干涉仪的判据、最优动量转移及灵敏度下限，指出无镜优势主要限于短基线仪器。
中文摘要 AI 辅助
大动量转移（LMT）可将光脉冲原子干涉仪的引力相位提升n倍，而无镜操作结合动量分辨探测能使携带相位的量子费舍尔信息提升4倍。实际中这两种增益存在竞争，因为动量空间的条纹周期与1/n成正比，条纹信号对有限探测器分辨率的敏感性会随n增大而提升。我们在可解模型中分析了这种权衡，该模型包含瞬时无损耗n光子脉冲、高斯源和高斯探测模糊，可在Kasevich-Chu几何与无镜几何间连续插值。我们得到了模糊输出分布和经典费舍尔信息的闭式表达式，其中条纹相位平均近似的误差呈指数级抑制，与数值模拟的吻合度达10^-8量级。我们发现，仅当σ_p < 0.91 m/(n k_0 T)时，无镜操作才能超越相同动量转移的常规干涉仪。基于条纹的读出存在最优动量转移n* ≈ 0.93 m/(σ_p k_0 T)，以及与光子动量无关的分辨率受限灵敏度下限Δg ≈ 4.4 σ_p/(mT√N)。若不满足该判据，部分镜不对称可恢复部分增强，而基于布居数的读出对探测器模糊不敏感，最终在n足够大时更倾向于常规序列。对^87Rb传感器的估算表明，无镜优势主要局限于短基线仪器。
英文摘要
Large momentum transfer (LMT) enhances the gravitational phase of a light-pulse atom interferometer by a factor $n$, while mirrorless operation with momentum-resolved detection can quadruple the phase-carrying quantum Fisher information. These gains compete in practice because the momentum-space fringe period scales as $1/n$, making the fringe signal increasingly vulnerable to finite detector resolution. We analyze this trade-off in a solvable model with instantaneous lossless $n$-photon pulses, a Gaussian source, and Gaussian detection blur, allowing continuous interpolation between Kasevich--Chu and mirrorless geometries. Closed-form expressions for the blurred output distributions and classical Fisher information are obtained, with a fringe-phase averaging approximation whose error is exponentially suppressed and agrees with numerical simulations at the $10^{-8}$ level. We find that mirrorless operation surpasses a conventional interferometer with the same momentum transfer only when $σ_p < 0.91\,m/(n k_0 T)$. Fringe-based readout exhibits an optimal momentum transfer $n^* \simeq 0.93\,m/(σ_p k_0 T)$ and a resolution-limited sensitivity floor $Δg \simeq 4.4\,σ_p/(mT\sqrt{N})$, independent of photon momentum. When this criterion is not satisfied, partial mirror asymmetry can recover part of the enhancement, whereas population-based readout remains insensitive to detector blur and ultimately favors the conventional sequence at sufficiently large $n$. Estimates for $^{87}$Rb sensors show that the mirrorless advantage is primarily restricted to short-baseline instruments.
