MRI: Development of an Ultracold Potassium Rydberg Source for Experiments in Quantum Optics and Many-Body Physics

这笔拨款支持开发一种仪器，以在高度激发的量子力学轨道（里德伯态）中产生致密、冷的钾原子气体。原子气体的温度将低于绝对零度以上的千分之一度。在高激发态中，电子离原子核很远，并且极易受到外电场和其他原子的相互作用的影响。由于它们非凡的特性，高激发原子有可能为一系列量子力学系统的动力学提供见解。高激发钾原子的简单性质将使实验能够阐明化学量子控制和量子信息科学中感兴趣的基本量子过程。原子之间相互作用的强、远距离和非各向同性性质以及多原子系统动力学的测量与使用超冷原子和分子样品的凝聚态物理中正在进行的实验有关。该仪器将进行的实验将解决两个最重要的问题。第一个问题是，在强场的驱动下，简单的量子系统是如何表现的。第二个问题是，当存在复杂的多体相互作用时，光如何帮助或阻碍原子和分子之间的能量传递。这种独特的仪器将使一所小型大学能够通过实验进行变革性研究，这些实验可以补充世界上其他机构对其他原子和分子物种的研究。开发这台仪器需要设计和建造三个不同的组件，这些组件将被添加到产生冷基态原子的工作系统中。开发项目的主要目标如下：(1)稳定激发钾电子的激光器；(2)研制和构造一种能对原子施加可控电场的结构；(3)研制和建造一种能够测定仪器中单个原子能级的探测器。具体来说，PI现有的钾磁光阱（MOT）将增加以下组件：(1)稳定的紫外和红外激光器，用于通过中间5p能级逐步激发超冷钾原子从基态到里德堡态；(2)射频传输线，对与超高真空MOT兼容的原子施加场；(3)不干扰里德伯态的状态选择场电离探测器。该项目涉及广泛的学生培训。该项目将通过直接参与仪器开发和受项目影响的课程，影响科尔比学院许多本科生的教育。在将各个层次的本科生纳入他的研究项目方面，PI卓有成效。从事仪器开发的本科生将接受最先进的原子物理学和激光、电子、光学仪器、真空和射频技术以及计算机数据采集和控制系统方面的专业知识的培训。

This grant supports the development of an instrument to produce dense, cold, gases of potassium atoms in highly excited quantum mechanical orbits (Rydberg states). The atomic gases will have temperatures less than a thousandth of a degree above absolute zero. In highly excited states the electrons are very far from the nucleus, and are highly susceptible to interactions with external electric fields and other atoms.Because of their remarkable properties, highly-excited atoms have the potential to provide insights into the dynamics of an array of quantum mechanical systems. The simple properties of highly excited potassium atoms will allow experiments that elucidate fundamental quantum processes of interest in chemical quantum control and in quantum information science. The strong, long-range, and non-isotropic nature of the interactions between atoms and measurements of the dynamics of many-atom systems is connected to ongoing experiments in condensed matter physics that employ ultracold samples of atoms and molecules.The experiments that will be enabled by the instrument will address two overriding questions. The first question is how simple quantum systems behave when driven by strong fields. The second question is how energy transfer between atoms and molecules can be assisted or frustrated by light while in the presence of complex many-body interactions. The unique instrument will allow transformative research at a small college through experiments that complement research done in other atomic and molecular species at other institutions worldwide.Developing the instrument involves design and construction of three distinct components to be added to a working system that produces cold ground-state atoms. The main goals of the development project are the following: (1) stabilizing lasers for excitation of the potassium electrons; (2) developing and constructing a structure to apply controlled electric fields to the atoms; and (3) developing and constructing a detector that can determine the energy levels of the individual atoms in the apparatus. Specifically, the following components will be added to the PI's existing potassium magneto optical trap (MOT): (1) stabilized ultraviolet and infrared lasers for stepwise excitation of ultracold potassium atoms from the ground-state to Rydberg states via the intermediate 5p level; (2) a radiofrequency transmission line to apply fields to the atoms that are compatible with the ultra-high-vacuum MOT; and (3) a state-selective field-ionization detector that does not perturb the Rydberg states.The project involves extensive student training. The project will impact the education of many undergraduate students at Colby College both through their direct participation in instrument development and in classes affected by the project. The PI has been effective at integrating undergraduate students of all levels into his research program. Undergraduates working on the development of the instrument will receive training in state-of-the-art atomic physics and expertise in lasers, electronics, optical instrumentation, vacuum and radiofrequency technology, and computerized data acquisition and control systems.