Interferometric Quantum Scattering in a Juggling Atomic Clock

杂耍原子钟中的干涉量子散射

• 批准号: 0800233
• 负责人: Kurt Gibble
• 金额: $ 32.73万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0800233&HistoricalAwards=false
• 关键词: Interferometric; Quantum; Scattering; Juggling; Atomic

This experimental research program will precisely study quantum scattering of ultracold cesium atoms in an atomic clock that juggles clouds of atoms. The group has recently demonstrated a fundamentally new type of scattering experiment in which a cesium atom, prepared in a superposition two states, scatters off of atoms in another cloud launched in the atomic clock. Each state of the superposition experiences a scattering phase shift, a measure of the strength of the interaction between the atoms. By detecting only the scattered part of each atom's wave function, the difference of the scattering phase shifts is directly observed as a frequency shift of the clock. A unique feature of this technique is that the frequency shift is independent of the atomic density. The technique allows scattering measurements with atomic-clock-like accuracy. Measurements of atomic scattering lengths with unprecedented accuracy are expected. They will precisely study the scattering of the different ground-substates of cesium atoms as a function of collision energy and magnetic field to unambiguously constrain ultracold cesium-cesium interactions. They will measure threshold effects and try to identify Feshbach and shape resonances. They can also probe the frequency shifts due to juggling collisions, important for improving the stability of future clocks. Highly precise measurements of scattering phase shifts near a narrow Feshbach resonance may stringently constrain the time variation of fundamental constants, such as the electron-proton mass ratio.Broader impacts of this program include the training of graduate students and postdoctoral researchers in many areas of modern technology from lasers, electro-optics, radio-frequency and microwave techniques, ultra-high vacuum, and atomic clocks and frequency control. This group has significantly contributed to the development of atomic clocks, including laser-cooled rubidium clocks, space clock design, juggling atomic fountains, ultra-stable lasers for optical frequency clocks, and studies of microwave cavities and cold collisions. The proposed research will lead to higher accuracy and stability of the cesium clocks that realize the definition of the SI second. The work will impact the understanding of ultracold atom-atom interactions with a breakthrough in clarity and precision.

该实验研究计划将精确研究原子钟中超冷铯原子的量子散射，该原子钟可以操纵原子云。该小组最近展示了一种全新类型的散射实验，其中以两种叠加状态制备的铯原子从原子钟中发射的另一个云中的原子中散射出来。叠加的每个状态都会经历散射相移，这是原子之间相互作用强度的度量。 通过仅检测每个原子波函数的散射部分，散射相移的差异被直接观察为时钟的频移。该技术的一个独特之处在于频移与原子密度无关。该技术允许以原子钟般的精度进行散射测量。预计将以前所未有的精度测量原子散射长度。他们将精确研究铯原子不同基态的散射作为碰撞能量和磁场的函数，以明确限制超冷铯-铯相互作用。他们将测量阈值效应并尝试识别 Feshbach 和形状共振。它们还可以探测由于杂耍碰撞而产生的频移，这对于提高未来时钟的稳定性非常重要。 对窄费什巴赫共振附近的散射相移进行高精度测量可以严格限制基本常数的时间变化，例如电子-质子质量比。该计划的更广泛影响包括在激光、电光、射频和微波技术、超高真空和原子钟等现代技术的许多领域对研究生和博士后研究人员进行培训 和频率控制。该小组对原子钟的发展做出了重大贡献，包括激光冷却铷钟、太空钟设计、杂耍原子喷泉、光频钟超稳定激光器以及微波腔和冷碰撞的研究。所提出的研究将提高铯钟的精度和稳定性，从而实现国际单位制秒的定义。这项工作将在清晰度和精度方面取得突破，影响对超冷原子间相互作用的理解。