Microwave Atom Chip Traps for Atom Interferometry

这个跨学科项目将设计、构建和表征基于微波原子芯片上超冷捕获原子的原子干涉仪。原子干涉仪是迄今为止最灵敏的力测量装置。值得注意的是，它们特别适合于精确测量和检测电场和磁场，重力和惯性力，如加速度和旋转。原子干涉仪的应用包括在没有gps的环境中进行惯性导航，对地下和水下结构进行遥感，测量原子表面力，以及寻找引力偏离平方反比定律。虽然大多数原子干涉仪使用自由传播的原子，但该项目的主要科学目标之一是开发和评估基于原子芯片设备上捕获的原子的原子干涉仪，这是构建紧凑，可现场传感器的理想选择。此外，该项目将使用AC塞曼势（基于快速振荡磁场）来控制这些原子，这是一种新颖且很少被探索的量子控制机制，用于利用原子芯片附近产生的微波场对原子施加力。研究生和本科生的研究人员将接受原子干涉测量学、超冷原子技术、微波工程和微制造技术以及原子和光学物理等广泛应用的科学方面的培训。这个跨学科项目是威廉玛丽大学的超冷量子物理学家和弗吉尼亚联邦大学的微制造工程师之间的合作成果。更具体地说，本项目将构建基于微波交流塞曼陷阱和微波原子芯片产生的势的超冷捕获原子干涉仪。该研究采用跨学科的方法，结合了材料科学的进步，微制造和微波工程，从根本上增强了超冷原子的自旋特定量子控制，用于捕获和干涉测量。该项目的一个主要目标是微波原子芯片的微制造：该芯片使用一种新型的氮化铝薄衬底，它具有大介电常数和高导热性，用于产生强微波近场。此外，AC塞曼势为超冷原子的自旋特异性操作提供了一种转换机制，该项目的主要目标是实现和研究基于原子芯片的微波AC塞曼阱，并评估其用于自旋相关原子干涉测量的适用性。值得注意的是，该项目将研究捕获原子自旋态的稳定性，捕获势的平滑性，额外的微波和射频修整场用于雕刻复杂势的应用，以及更紧凑的芯片结构的可行性。最后，该项目将研究微波晶格用于增强捕获和干涉测量的使用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This interdisciplinary project will design, construct, and characterize atom interferometers based on ultracold trapped atoms on a microwave atom chip. Atom interferometers are the most sensitive force measuring devices ever constructed. Notably, they are particularly well suited for precision measurements and detection of electric and magnetic fields, gravity, and inertial forces, such as accelerations and rotations. Applications of atom interferometers include inertial navigation in a GPS-denied environment, remote sensing of underground and underwater structures, measuring atom-surface forces, and searching for deviations of the gravitational force from the inverse square law. While most atom interferometers operate with freely propagating atoms, one of the main scientific goals of this project is to develop and evaluate atom interferometers based on atoms trapped on an atom chip device, ideal for building a compact, fieldable sensor. Furthermore, the project will control these atoms using AC Zeeman potentials (based on rapidly oscillating magnetic fields) a novel and little explored quantum control mechanism for applying forces on atoms using microwave fields generated in the vicinity of an atom chip. Graduate and undergraduate student researchers will be trained in atom interferometry, ultracold atom technologies, microwave engineering, and micro-fabrication techniques, as well as in the broadly enabling sciences of atomic and optical physics. This interdisciplinary project is a collaborative effort between ultracold quantum physicists at William & Mary and microfabrication engineers at Virginia Commonwealth University. More specifically, this project will construct ultracold trapped atom interferometers that are based on microwave AC Zeeman traps and potentials generated by a microwave atom chip. The research uses an interdisciplinary approach that combines materials science advances, microfabrication, and microwave engineering to fundamentally enhance spin-specific quantum control of ultracold atoms for trapping and interferometry. A major objective of this project is the microfabrication of a microwave atom chip: The chip uses a novel thin substrate of aluminum nitride, which has a large dielectric constant and high thermal conductivity, for generating strong microwave near fields. Furthermore, AC Zeeman potentials offer a transformational mechanism for spin-specific manipulation of ultracold atoms, and a major thrust of the project is to implement and study atom chip-based microwave AC Zeeman traps and evaluate their suitability for spin-dependent atom interferometry. Notably, the project will study the stability of trapped atomic spin states, the smoothness of the trapping potential, the application of additional microwave and radio-frequency dressing fields for sculpting complex potentials, and the viability of more compact chip structures. Finally, the project will investigate the use of microwave lattices for enhanced trapping and interferometry.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.