Quantum Dynamics of Soliton-Pair Creation in Quasi-One-Dimensional Halogen-Bridged metal Complexes

准一维卤桥金属配合物中孤子对产生的量子动力学

基本信息

批准号：
10640319
负责人：
IWANO Kaoru
金额：
$ 2.05万
依托单位：
High Energy Accelerator Research Organization
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

In this project we have estimated the probability of the non-radiative transition from the relaxed state (confined soliton and antisoliton) in the first excited state to the ground state, in the framework of a non-degenerate charge-density-wave(CDW) model.All through this project, the main problem has been how to incorporate modes of phonons which are ruling the degree of non-adiabatic transitions. In the first year, we only treated the relative coordinate between the soliton and the antisoliton to find that the obtained probability was very small and so the selection was not enough. By detailed analysis, we clarified that the reason was the lack of long-wave phonons which are very closely related to the concerned transition. Therefore we tackled with the problem of how to include such many modes, in the second year.As the first method, we have added the amplitude of a deformation localized around the solitons as the second mode. Here the deformation is prepared to consist mainly of the modes close to k=0. Thus the purpose of this method is to check the prediction in the first year. As a result, the probability drastically increases to give the life time of about 8.6 ns for a certain parameter set. (Cf : it was about 12 ms in the case of one-coordinate treatment)Next, we have included cosine-type modes, instead of the localized mode. Such modes are added from the k=o one in increasing order. Fortunately, modes with different wave numbers can be treated almost independently. Thus, their contributions become additive without any interference with each other. In this situation, we have increased the number of modes from 1 to 40 in the system with 200 sites. As a result, the probability almost reaches to saturation at the number of 25. Finally, we have obtained the value of 110 ps as the life time, which is consistent with the result by the semi-classical method, namely, 80 ps.

在这个项目中，我们估计了在非简并电荷密度波（CDW）的框架内从第一激发态的松弛态（受限孤子和反孤子）到基态的非辐射跃迁的概率在整个项目中，主要问题是如何合并决定非绝热跃迁程度的声子模式。第一年，我们只处理了孤子和反孤子之间的相对坐标，发现得到的概率很小，所以选择不够。通过详细分析，我们明确了原因是缺乏与跃迁密切相关的长波声子。因此，我们在第二年解决了如何包含如此多的模式的问题。作为第一种方法，我们添加了孤子周围局部变形的幅度作为第二模式。这里准备的变形主要由接近 k=0 的模式组成。因此，该方法的目的是检查第一年的预测。因此，某个参数集的寿命达到约 8.6 ns 的概率急剧增加。（cf：在单坐标处理的情况下约为 12 ms）接下来，我们包括余弦型模式，而不是局部模式。这些模式是从 k=o 模式开始按升序添加的。幸运的是，具有不同波数的模式几乎可以独立处理。因此，它们的贡献可以累加，彼此之间不会产生任何干扰。在这种情况下，我们在200个站点的系统中将模式数量从1种增加到40种。结果，在数量为25时，概率几乎达到饱和。最终，我们得到了110 ps作为寿命值，这与半经典方法的结果一致，即80 ps。