| 题名 | 稀土金属团簇的原子结构及微结构势阱中冷原子的动力学行为 |
| 作者 | 罗有华 |
| 学位类别 | 博士后 |
| 答辩日期 | 2003 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 王育竹 |
| 关键词 | 稀土金属团簇，原子结构，冷原子，微结构势阱 |
| 其他题名 | Atomic Structure of Rare-Earth Metallic Clusters and Dynamical Behavior of Cold Atoms in Periodic Microtraps |
| 中文摘要 | 这个报告包含两部分内容:稀土金属团簇的原子结构及微结构势阱中冷原子的动力学行为。在第一部分，我们采用莫比乌斯反演对势和遗传算法，预言了稀土金属团簇LaN,CeN和PrN直到尺寸N=20的最低能量结构，获得了这些团簇的对称性，平均结合能以及最近邻原子间距。结果表明，在同一尺寸LaN, CeN和PrN团簇具有相同的点群。对称性最高的团簇分别是LaN, CeN和PrN，同时，它们也是最稳定的团簇;而La20, Ce20和Pre20的对称性最低，属无序结构。与尺寸N=4, 6, 11和15对应的团簇在结构上是相对稳定的。在第二部分，我们采用分子动力学方法，分别模拟了冷原子在带电金属网格和载流金属网格中的动力学行为。模拟和计算表明，在带电金属网格近表面不可能形成三维周期微结构势阱;在载流金属网格近表面可以形成三维周期微结构势由于塞曼效应，处于弱场寻找态的冷原子可以被囚禁起通过改变磁场梯度的大小，可以增加冷原子在势阱中的阱来寿命。另外，用量子力学方法计算了冷原子在微结构势阱中的振动能级。 |
| 英文摘要 | This report consists of two parts including atomic structure of the are-earth metallic clusters and dynamical behavior of cold atoms in periodic microtraps. In first part the Mobius inversion pair potential has been employed, in combination with genetic algorithms，to predict the lowest-energy structures of the rare-earth metallic clusters LaN} CeN, and PrN(N=3-20 ). Results are given for the symmetries } binding energies， nearest-neighbor distances of these clusters，and lowest-energy configurations of CeN clusters. Also，the calculated second finite difference of the total energy shows that for three species elements，the 13-atom clusters with symmetry are particularly stable. Some minor peaks are also found at size N=4，6，11，and 15，which indicates that the corresponding clusters are relatively stable in structure. In second part, the molecular dynamics method has been used to simulate the namical behavior of cold atoms in charged and current-carrying metallic webs，respectively. We found that in charged metallic web， 3-dimensional periodic microtraps can not be abricated，and in current-carrying metallic web，such microtraps fabricated. Based on Zeeman effect, for laser-cooled atoms，they can be trapped in such microtraps. In this case，the trapped atom is in the weak-field seeking state or low-field seeking state. Namely, the cold atoms are trapped in a local minimum of the magnetic field. By adjusting the magnitude of magnetic field gradient the lifetime of cold atoms in the microtraps can be increased. In addition, for the cold atom in a trap，the vibrational levels were calculated by means of using quantum mechanics method. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16039]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 罗有华. 稀土金属团簇的原子结构及微结构势阱中冷原子的动力学行为[D]. 中国科学院上海光学精密机械研究所. 2003. |
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