Microwave Traps and Atom Interferometry with AC Zeeman Potentials

该项目将开发和表征基于原子芯片上的超冷捕获原子的原子干涉仪。原子干涉仪是有史以来最灵敏的测力设备，非常适合电场、磁场、重力和惯性力(如加速度和旋转)的精确测量和检测。原子干涉仪的应用包括在没有GPS的环境中进行惯性导航，对地下结构进行遥感，测量原子表面力，以及搜索引力与平方反比定律的偏差。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捕获原子的原子干涉仪。此外，该项目将使用交流塞曼势来控制这些原子，这是一种新颖的量子控制机制，利用原子芯片附近产生的微波场对原子施加力。研究生和本科生研究人员将接受原子干涉计量学、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的广泛使能科学方面的培训。更具体地说，该项目将建造能够与良好局部化、可定位的原子包进行长相位积分时间的超冷囚禁原子干涉仪。这些被捕获的原子干涉仪将是自旋相关的，因此干涉仪的两个臂具有不同量子自旋态的原子。这种自旋相关性将使干涉仪能够使用许多不同空间状态的原子，以便它可以使用超冷热原子或简并费米子，这有望抑制原子与原子的相互作用。该项目将使用原子芯片产生的微波近场产生的交流塞曼势来实现干涉仪的自旋依赖力和陷阱。值得注意的是，该项目将设计和微制造一种微波原子芯片，以有效地产生交流塞曼电势。该项目的一个重要目标是开发和表征AC塞曼陷阱和势能，并因此对它们进行评估，以纳入超冷原子物理技术的工具箱。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project will develop and characterize atom interferometers based on ultracold trapped atoms on an atom chip. Atom interferometers are the most sensitive force measuring devices ever constructed and are 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 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 trapped atoms. Furthermore, the project will control these atoms using AC Zeeman potentials, 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.More specifically, this project will construct ultracold trapped atom interferometers that are capable of long phase integration times with well localized, positionable atomic packets. These trapped atom interferometers will be spin-dependent so that the two arms of the interferometer have atoms in different quantum spin states. The spin-dependence will enable the interferometer to use atoms in many different spatial states so that it can employ ultracold thermal atoms or degenerate fermions, which are expected to suppress atom-atom interactions. The project will use AC Zeeman potentials generated by microwave near-fields from an atom chip to implement the spin-dependent forces and traps for the interferometer. Notably, the project will design and micro-fabricate a microwave atom chip for efficient generation of AC Zeeman potentials. An important objective of this project is to develop and characterize AC Zeeman traps and potentials, and thus evaluate them for inclusion in the toolbox of ultracold atomic physics techniques.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.