Theoretical study of anomalous fluctuation and it's effects on dynamical properties of one-dimensional conductors

反常涨落及其对一维导体动力学特性影响的理论研究

基本信息

批准号：
15540343
负责人：
YOSHIOKA Hideo
金额：
$ 1.92万
依托单位：
Nara Women's University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

In collaboration with the experimental group, we directly observed the density of state of carbon nanotubes by the photo emission study. It was shown that Tomonaga-Luttinger liquid state is realized in the carbon nanotubes in the wide range of the temperature from 10 K to room temperature. The nano-graphite ribbons are known to have the anomalous dispersion relation near the Fermi energy different from the usual metals. We investigated the electronic correlation of the materials. It was shown that the mutual interaction leads to Mott insulating ground state and the spin excitation becomes gapless (gapped) for the odd (even) number of zigzag chains.2.Splitting of the Knight shift and of the NMR relaxation rate have been considered to be the experimental evidence of charge ordering in the molecular conductors. In the case of quarter-filling, however, no one show theoretically that the charge ordering leads to such phenomena. In the present study, we calculated the Knight shift and the NM … More R relaxation rate in the pure charge ordered state of one-dimensional extended Hubbard model. Here, the fluctuation around the mean-field solution is taken into account by RPA. It is shown that the both quantities show splitting under the charge ordering, as has been already insisted. In addition, the amount of charge disproportionation estimated from the NMR experiments becomes larger than the actual value.3.Quite recently, the materials with incommensurate decomposition ratios close to 2:1 such as (MDT-TSF)_2X_n, (MDT-ST)_2X_n, and (MDT-TS)_2X_n with X being a monovalent anion and n=0.42〜0.45 have been synthesized and the transport and magnetic properties of these compounds have been measured. The materials (MDT-TSF)_2X_n and (MDT-ST)_2X_n show metallic conduction and undergo the superconducting transition at 4 K for ambient pressure. On the other hand, (MDT-TS)_2(AuI_2)_<0.441> shows the metal-insulator transition at 85 K. In order to clarify why the metal-insulator transition occurs in the case of incommensurate band filling, we investigated the ground state of one-dimensional extended Hubbard model with incommensurate lattices. When the potential from the anions is taken into account, the ground state is Mott insulator, and the increase of band width leads to metal-insulator transition. These results will qualitatively explain the experimental observation shown above. Less

与实验组合作，我们通过照片排放研究直接观察到碳纳米管的密度丝带是Fermi能量附近的异常散布关系，与通常的金属不同。 NMR弛豫率在分子导体中被认为是电荷的经验证据。电荷提供了一维的扩展哈伯德模型，RPA考虑了RPA的均值，并坚持使用Alleyady。。这些化合物的转运和磁性已舒适。 ts）_2（AUI_2）_ <0.441>显示了85 K处的金属 - 绝缘体过渡。这些

项目成果

期刊论文数量（60）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Theoretical Aspects of Charge Ordering in Molecular Conductors

分子导体中电荷排序的理论方面

DOI：
发表时间：
期刊：
Journal of the Physical Society of Japan (in press)
影响因子：
0
作者：
H.Seo;J.Merino;H.Yoshioka;M.Ogata
通讯作者：
M.Ogata

Valence-Band Photoemission Study of Single-Wall Carbon Nanotubes

单壁碳纳米管的价带光电研究

DOI：
发表时间：
2003
期刊：
AIP Conference Proceedings 685
影响因子：
0
作者：
H.Shiozawa et al.;(全16名)
通讯作者：
(全16名)

Theoretical Study on Knight Shift and Nuclear Spin Relaxation Rate in the Charge Ordering State of the ID Quarter-filled Electron System

ID 1/4填充电子系统电荷有序态下奈特位移和核自旋弛豫率的理论研究

DOI：
发表时间：
期刊：
Journal of Low Temperature Physics (印刷中)
影响因子：
0
作者：
H.Yoshioka;H.Hashizume;H.Yoshioka;H.Shiozawa et al.;H.Yoshioka;H.Ishii et al.;H.Yoshioka
通讯作者：
H.Yoshioka

H.Yoshioka, Y.Hashizume: "Charge ordering and Knight shift in one-dimensional electron systems nearly half-filling"Journal de Physique IV. (印刷中).

H.Yoshioka，Y.Hashizume：“一维电子系统中的电荷排序和奈特位移接近半填充”Journal de Physique IV（出版中）。