Experiments Using Long Coherence Times in Atoms

项目实验将利用激光与原子的相互作用来探索基本粒子和核物理中最基本的问题。一项实验将以前所未有的灵敏度寻找汞原子正负电荷中心之间的微小分离。这种“电偶极子”的存在将违反时间逆转和物质/反物质对称性，并有助于解释宇宙中物质比反物质占优势的原因。另一个实验将测量镱原子在吸收光时的反冲，从而测试基本量子电动力学的有效性，其精度优于十亿分之一。此外，一个单钡原子离子的实验将通过比以往更精确地测量原子核的形状来探测核力的本质。这些实验为更广泛的社区和实际应用开辟了道路。时间逆转和反物质的概念吸引了大众。解决这些问题的汞实验需要开发可用于医学的超灵敏磁强计。当人们用肉眼或照片看到单个捕获的钡离子，然后发现这个离子可以作为导航的精确时钟时，他们会感到兴奋。在物理学中，这些实验涉及广泛的领域：原子、核、高能和天体物理学。它们吸引了许多研究生和本科生，因为他们有机会在当地进行小规模实验，探索通常只有在高能加速器上进行大规模研究的基本问题。这些学生获得了原子、激光和电子等尖端技术的经验，并反过来帮助他们在未来的职业生涯中取得这些技术的进步。

Project experiments will utilize the interaction of laser light with atoms to explore the most fundamental issues in elementary particle and nuclear physics. One experiment will search with unprecedented sensitivity for a tiny separation between the centers of plus and minus charge of the mercury atom. The existence of such an 'electric dipole' would violate time-reversal and matter/anti-matter symmetries and would help explain the preponderance of matter over anti-matter in the Universe. Another experiment will measure the recoil of Ytterbium atoms when they absorb light, and thereby test the validity of basic quantum electrodynamics to better than a part per billion. Also, an experiment with a single barium atomic ion will probe the nature of the nuclear force by measuring the shape of an atomic nucleus more precisely than ever before.These experiments open up avenues to the wider community and also to practical applications. The notions of time reversal and anti-matter appeal to the general public. The mercury experiment that addresses these issues requires developing ultra-sensitive magnetometry that could be used in medicine. People are excited when they see a single trapped barium ion with the naked eye, or in a photograph, and then find out that this ion can be an accurate clock for navigation. Within physics these experiments touch a broad community: atomic, nuclear, high energy, and astrophysics. They attract many graduate and undergraduate students for the chance to work locally on small-scale experiments and explore fundamental issues normally studied only by large groups at high energy accelerators. These students gain experience in exquisite technology with atoms, lasers and electronics, and in turn help make advances in this technology that they take with them to their future careers.