RUI Collaboration: Designing Ultra-cold Atom Circuits in Quasi-2D Confinement

这个理论研究项目将由乔治亚南方大学的马克·爱德华兹博士和联合量子研究所（JQI）的查尔斯·w·克拉克博士合作进行，联合量子研究所是由马里兰大学和国家标准与技术研究院（NIST）联合运营的。将致力于设计和研究新的“原子电路”，以开发超精密旋转传感器，并在超冷温度下对量子物质有更大的基本了解。“原子电路”是一种受激光约束的原子气体，其温度仅比绝对零度高几十亿分之一度。由相同原子组成的气体被限制在如此低的温度下，导致组成原子表现出波状量子性质，气体可以形成一种称为“玻色-爱因斯坦凝聚”（BEC）的状态。BEC是一个由相同原子组成的系统，所有原子的物质波形状都是相同的。玻色-爱因斯坦凝聚态气体可以被限制激光操纵成任意形状，如环，原子可以在限制内的电路中流动。这种系统被称为“原子电路”。这些电路有可能成为量子设备的核心，以超精确的方式感知旋转、磁场和引力场。该研究计划将设计新的原子电路，并开发表征和探测它们的理论工具。这项工作将与JQI/NIST的实验研究人员密切合作。该研究项目旨在使两位才华横溢的佐治亚南方大学物理学本科专业的学生获得在超冷原子理论领域的前沿研究经验，从而在促进学习的同时推进发现。爱德华兹和佐治亚南方大学的学生将使用谷歌Hangout与查尔斯·克拉克领导的JQI研究小组以及格雷琴·坎贝尔领导的NIST激光冷却和捕获小组成员进行交流。佐治亚南方大学的学生将通过互联网参加每周一次的量子信息/玻色-爱因斯坦会议。该项目将通过维持本科机构（GA Southern）、国家实验室（NIST）和主要研究型大学（马里兰大学）之间的既定合作，加强研究和教育的基础设施。将通过邀请杰出的科学家到佐治亚南方大学校园进行讨论会，并通过佐治亚南方天文馆的新数字投影系统开发可视化能力，来实现广泛的传播，以加强科学和技术的理解。最后，新的原子电路有可能成为新一代实用设备的核心，这些设备将在导航、计量、大地测量和物质基本性质的研究中得到应用。这项合作将对各种原子电路的设计进行理论探索，这些原子电路是通过将玻色-爱因斯坦凝聚（BEC）气体限制在由水平方向的红色失谐光片和由各种红色和蓝色失谐激光束产生的平面内任意二维势组成的光势中形成的。光学捕获技术的进步使得超冷原子系统在垂直方向上受到强烈限制，同时在水平面上受到任意电位的影响。新的原子电路电位将被设计和研究。对这些系统的研究将包括(1)电路行为，(2)发展类似于电子电路基尔霍夫规则的简单电路运行模型，(3)理论发展可能的实验探针来测量这些简单模型中出现的参数，(4)环境（如有限温度）对电路运行的影响。将开发的主要工具是实验室中的Zaremba-Nikuni-Griffin （ZNG）理论和旋转框架。ZNG理论将系统视为BEC和热云的结合，热云可以被弱扰动。结果是一个有限温度的非平衡系统。

This theoretical research program, to be performed by a collaboration between Dr. Mark Edwards of Georgia Southern University and Dr. Charles W. Clark of the Joint Quantum Institute (JQI), an institute run jointly by the University of Maryland and the National Institute of Standards and Technology (NIST), will be devoted to the design and study of new "atom circuits" for the purpose of developing an ultra-precise rotation sensor and for gaining a greater fundamental understanding of quantum matter at ultra-cold temperatures. An "atom circuit" is an atomic gas confined by laser light and held at temperatures just a few billionths of a degree above absolute zero. Gases of identical atoms confined at such low temperatures cause the constituent atoms to exhibit their wave-like quantum nature and the gas can form a state called a "Bose-Einstein condensate" (BEC). A BEC is a system of identical atoms all of whose matter-wave shapes are the same. Bose-Einstein-condensed gases can be manipulated by the confining laser light into arbitrary shapes such as rings and the atoms can be made to flow around circuits within the confinement. Such systems are called "atom circuits". These circuits have the potential to be at the heart of quantum devices that can sense rotations and magnetic and gravitational fields in an ultra-precise way. This research program will design new atom circuits and develop theoretical tools for characterizing and probing them. This work will performed in close collaboration with experimental researchers at JQI/NIST.This research program is designed to enable two talented Georgia Southern University undergraduate physics majors to gain cutting-edge research experience in the area of ultra-cold atom theory thus advancing discovery while promoting learning. Edwards and the Georgia Southern students will communicate with both the JQI research group headed by Charles Clark and with members of the Laser Cooling and Trapping group at NIST, headed by Gretchen Campbell, using Google Hangout. Georgia Southern students will attend the weekly Quantum Information/Bose-Einstein meetings at NIST via the internet. The project will enhance the infrastructure for research and education by maintaining an established collaboration among an undergraduate institution (GA Southern), a national laboratory (NIST), and a major research university (University of Maryland). Broad dissemination to enhance scientific and technological understanding will be accomplished by bringing distinguished scientists to the Georgia Southern University campus to present colloquia and by developing visualization capabilities with the new digital projection system in the Georgia Southern Planetarium. Finally, new atom-circuits have the potential to be at the heart of a new generation of practical devices that will find applications in navigation, metrology, geodesy, and studies of the fundamental properties of matter.This collaboration will conduct a theoretical exploration of various designs of atom circuits formed by confining a Bose-Einstein condensate (BEC) gas in an optical potential consisting of a horizontally oriented red-detuned light sheet and an arbitrary two-dimensional potential within this plane created by various red- and blue-detuned laser beams. Advances in optical trapping technology have enabled the creation of ultra-cold atom systems strongly confined in the vertical direction while being subject to an arbitrary potential in the horizontal plane. New atom-circuit potentials will be devised and studied. Studies of these systems will include (1) circuit behavior, (2) development of simple models of circuit operation analogous to Kirchhoff's rules for electronic circuits, (3) theoretical development of possible experimental probes to measure parameters appearing in these simple models, (4) effects of the environment, such as finite temperature, on circuit operation. The major tools that will be developed will be the Zaremba-Nikuni-Griffin (ZNG) theory in the laboratory and rotating frame. The ZNG theory treats the system as a combination of a BEC and a thermal cloud that can be weakly perturbed. The result is a finite-temperature, non-equilibrium system.