Observation of millihertz-level cooperative Lamb shifts in an optical atomic clock

• 成果类型: Article
• 署名作者: Hutson, Ross B.; Milner, William R.; Yan, Lingfeng; Ye, Jun; Sanner, Christian
• 署名单位: National Institute of Standards & Technology (NIST) - USA; University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder; Colorado State University System; Colorado State University Fort Collins
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-13676
• DOI: 10.1126/science.adh4477
• 发表日期: 2024-01-26
• 页码: 384-387
• 关键词: radiation; superradiance; fluctuations; noise

摘要

Collective couplings of atomic dipoles to a shared electromagnetic environment produce a wide range of many-body phenomena. We report on the direct observation of resonant electric dipole-dipole interactions in a cubic array of atoms in the many-excitation limit. The interactions produce spatially dependent cooperative Lamb shifts when spectroscopically interrogating the millihertz-wide optical clock transition in strontium-87. We show that the ensemble-averaged shifts can be suppressed below the level of evaluated systematic uncertainties for optical atomic clocks. Additionally, we demonstrate that excitation of the atomic dipoles near a Bragg angle can enhance these effects by nearly an order of magnitude compared with nonresonant geometries. Our work demonstrates a platform for precise studies of the quantum many-body physics of spins with long-range interactions mediated by propagating photons.