Rydberg-Atom Physics in Ponderomotive Traps and Atomic Imaging Devices

在“有质运动陷阱和原子成像器件中的里德堡原子物理”项目中，对里德堡原子的光学晶格偶极子陷阱进行了改进和应用研究。这些光学陷阱具有陷阱诱导的能级漂移，比静场陷阱的能级移动小得多。因此，它们非常适合目前高度感兴趣的高精度光谱学和量子信息处理应用。晶格显示出丰富的绝热陷阱势，这是通过激光光谱学研究的。测量了晶格诱导光致电离对俘获里德堡原子的影响。发展了一种基于光学晶格光束的微波调制的光谱方法。该方法允许研究团队驱动高阶多极跃迁，而无需应用会导致能级漂移的大场，并具有高空间分辨率。该研究小组开发了三维光学晶格，用于光学捕获的圆形里德堡原子的微波光谱。这项工作有可能产生高精度的里德堡常数测量。在工作的第二部分，尖端成像探头(TIP)被用于对多体里德堡系统中的关联进行空域测量。在这些系统中，处于高度纠缠的量子态中的大量冷原子之间相干地共享几个非定域里德堡激发。TIP系统通过离子成像读出样品中单个里德堡激发的位置。通过尖端设置的新测量，研究人员可以在测量信号中分离封锁诱导效应和库仑离子排斥效应。TIP实验被应用于在随机分布的基态原子样品中制备和检测绝热通道激发的里德堡原子晶体，捕获单个原子仍然是原子、分子和光学物理中的一个主要主题。在所谓的“光学晶格”中，几束相交的激光被用来形成一个周期性的陷阱位置网格，以捕获原子。光学晶格很像一个鸡蛋盒，在周期性的位置上装鸡蛋(鸡蛋是原子的类似物)。在这个项目中，密歇根的一个研究团队为里德堡原子开发了这样的光学晶格。里德堡原子是一个巨大的原子，它有一个非常松散的电子，平均而言，它会离开原子的中心很远。研究界认为，从长远来看，激光陷阱中的里德堡原子可以帮助开发功能强大的量子计算机，这种计算机可以处理普通计算机无法解决的数学问题。密歇根团队开发的光学里德堡原子陷阱也有可能产生关于基本常数的信息，例如里德伯格常数。对这些常数的测量具有很大的价值，因为它们是对我们目前对物质组成和自然内部工作原理的理解的测试。在该项目中，研究生和本科生接受研究、研究报告和同行指导方面的培训。作为一个整体，该项目对社会产生了更广泛的影响，因为各级学生都准备好承担科学、工业和教育领域的重要任务。该项目伴随着旨在鼓励高中生考虑从事科学或工程职业的外联活动，例如密歇根物理奥林匹克竞赛。

In the project entitled "Rydberg-atom physics in ponderomotive traps and atomic imaging devices" optical-lattice dipole traps for Rydberg atoms are developed, improved and applied in research. These optical traps have trap-induced level shifts that are much smaller than those in static-field traps. They are therefore well suited for high-precision spectroscopy and quantum information processing applications that are currently of high interest. The lattices exhibit a rich variety of adiabatic trapping potentials, which are studied via laser spectroscopy. The effect of lattice-induced photo-ionization on the trapped Rydberg atoms is measured. A spectroscopic method is developed that is based on microwave modulation of the optical-lattice beams. The method allows the research team to drive high-order multipole transitions without the application of large fields, which would cause level shifts, and with high spatial resolution. The research team develops three-dimensional optical lattices for microwave spectroscopy of optically trapped circular-state Rydberg atoms. The work has the prospect of yielding a high-precision measurement of the Rydberg constant.In the second component of the work, a tip imaging probe (TIP) is employed to perform spatial-domain measurements of correlations in many-body Rydberg systems. In these systems, several de-localized Rydberg excitations are coherently shared between a large number of cold atoms in a highly entangled quantum state. The TIP system reads out the positions of individual Rydberg excitations in the sample via ion imaging. New measurements with the TIP setup allow the researchers to separate blockade-induced effects and effects due to Coulomb ion repulsion in the measured signals. The TIP experiment is applied to prepare and detect Rydberg atom crystals excited by adiabatic passage in randomly distributed samples of ground-state atoms.Trapping individual atoms continues to be a major theme in atomic, molecular and optical physics. In a so-called "optical lattice," several intersecting laser beams are used to form a periodic grid of trap sites to trap atoms. An optical lattice is much like an egg carton holding eggs at periodic locations (where an egg is the atom's analogue). In this project a Michigan research team develops such optical lattices for Rydberg atoms. A Rydberg atom is a giant atom with one very loosely bound electron that travels, on average, quite far away from the atom's center. The research community believes that, in the long term, Rydberg atoms in laser traps can be helpful in the development of powerful quantum computers, which can treat mathematical problems that ordinary computers cannot solve. The optical Rydberg atom traps the Michigan team develops also have the potential of yielding information on fundamental constants, such as the Rydberg constant. Measurements of such constants are of great value because they serve as tests of our current understanding of the composition of matter and the inner workings of nature. In the project, graduate and undergraduate students are trained in research, research presentation, and in peer instruction. The project as a whole has a broader impact on society in that students at all levels become prepared to assume important tasks in science, industry and education. The project is accompanied by outreach components that aim to encourage high-school students to consider careers in science or engineering, such as the Michigan Physics Olympiad.