原子光钟跃迁性质的相对论耦合簇理论计算

项目名称： 原子光钟跃迁性质的相对论耦合簇理论计算

项目编号： No.61275129

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 于艳梅

作者单位： 中国科学院物理研究所

项目金额： 50万元

中文摘要： 束缚单离子光钟和光晶格原子光钟将时间频率的定义提高到极限水平。在这个层次上，原子光频标的不准确度和稳定性受到更细微的影响因素的限制。为了确定新一代的时间频率标准，影响原子光频标的钟频率跃迁性质的高阶小量必须经过评估、计算和修正。 目前原子光钟的候选原子包括Ca+,Al+,Hg+,Sr,Yb等，大都具有复杂的电子多重态和准简并性，旋轨耦合效应使高精度价电子能谱和跃迁性质的计算问题更加复杂。在这样的背景下，我们选择束缚单离子和光晶格中性原子为研究对象，发展基于束缚态量子电动力学理论的多电子体系精密能谱计算方法，考虑相对论效应和多电子相干效应，研究Ca+,Al+,Hg+,Sr,Yb等的跃迁性质，计算磁、光、电外场扰动下原子和离子跃迁能级的各种高阶小量，如二阶塞曼频移、斯塔克频移、电四极频移，光频移和寻找魔波长，为我国原子光频标的实验误差物理起源的分析以及不准确度和稳定性评估提供理论数据。

中文关键词： 光钟；相对论耦合簇计算；背景黑体辐射频移；电四极矩频移；高价离子

英文摘要： Optical frequency standards based on single a trapped ion or neutral atoms in optical lattice can reach a systematic fractional uncertainty above the order of 10-18. Some of the successful single-ion optical atomic clocks include Ca+, Hg+, Al+, etc, and the successful optical-lattice clocks include Sr and Yb. A new range of experiments are also proposed for other ions or neutral atoms like Ba+, Ra+, In+, Yb+, Mg, and Ca, etc. More precise time and frequency standards will open up possibilities to study the underlying physics related to fundamental constants, probing new elementary physics, and, more importantly, it can help in improving the present-day positing systems and also in tracking deep-space probes. At such high frequency level, the major contributions to systematic frequency uncertainty come from high-order perturbations of atomic state in the external magnetic, optical, and electric fields. Therefore, interests in the subject of high-precise calculation of atomic states has been recently elevated by the appreciation that the accuracy of next-generation atomic time and frequency standards, based on optical transition, is significantly limited by the displacement of atomic energy levels due to universal ambient fluctuations in the external fields. Determination of optical transition frequency depends o

英文关键词： atomic clock；relativistic couple cluster method；black body radiation shift；electric quadrupole shift；uncertainty of freqency