近日，美国加州大学的Holger Müller&Cristian D. Panda及其研究团队取得一项新进展。经过不懈努力，他们揭示一分钟尺度下晶格原子干涉测量的相干极限。相关研究成果已于2024年6月11日在国际知名学术期刊《自然—物理学》上发表。

该研究团队实现了一个原子干涉仪，其空间叠加态维持了长达70秒。研究人员分析了原子系综集体退相干引起的相干性的理论和实验限制。这表明，在保持时间超过几十秒时，退相干速率显著变缓。相干性的这些增益特性有望为引力测量、第五种力的搜索或对引力的非经典性质的基本探索成为可能。

据悉，在量子计量学和量子模拟中，必须在与环境的不必要相互作用导致退相干之前对相干非经典态进行操纵。在原子干涉测量中，非经典态是一种空间叠加态，其中每个原子作为相相干分波包的集合共存于多个位置。这些状态使基础物理和惯性传感的精确测量成为可能。然而，原子干涉仪通常使用原子喷泉，对于10米喷泉，可用的探测时间限制在3秒左右。

附：英文原文

Title: Coherence limits in lattice atom interferometry at the one-minute scale

Author: Panda, Cristian D., Tao, Matthew, Egelhoff, James, Ceja, Miguel, Xu, Victoria, Muller, Holger

Issue&Volume: 2024-06-11

Abstract: In quantum metrology and quantum simulation, a coherent non-classical state must be manipulated before unwanted interactions with the environment lead to decoherence. In atom interferometry, the non-classical state is a spatial superposition, where each atom coexists in multiple locations as a collection of phase-coherent partial wavepackets. These states enable precise measurements in fundamental physics and inertial sensing. However, atom interferometers usually use atomic fountains, where the available interrogation time is limited to around 3 s for a 10 m fountain. Here we realize an atom interferometer with a spatial superposition state that is maintained for as long as 70 s. We analyse the theoretical and experimental limits to coherence arising from collective dephasing of the atomic ensemble. This reveals that the decoherence rate slows down markedly at hold times that exceed tens of seconds. These gains in coherence may enable gravimetry measurements, searches for fifth forces or fundamental probes into the non-classical nature of gravity.

DOI: 10.1038/s41567-024-02518-9

Source: https://www.nature.com/articles/s41567-024-02518-9