权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Theoretical studies for the intrinsic Josephson effect and the collective excitations in high-Tc superconductors

高温超导体固有约瑟夫森效应和集体激发的理论研究

基本信息

批准号：
11640332
负责人：
KOYAMA Tomio
金额：
$ 1.79万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640332/
关键词：
high-Tc superconductors intrinsic Josephson effect Josephson plasma Coulomb blockade 電流・電圧特性

项目摘要

The CuO2 layers in high-Tc cuprates are responsible for the high-temperature superconductivity in these systems. The coupling between Cu02 layers in high-Tc superconductors is very weak. As a result, the Josephson effect appears in the c-axis transport phenomena even in single crystals of these superconductors, which is called the intrinsic Josephson effect. In this research project I have investigated theoretically the c-axis transport properties related to the intrinsic Josephson effects in high-Tc superconductors. I have constructed a complete quantum theory for the Josephson plasma oscillations observed in these superconductors. The effects of the quasi-particles on the plasma excitations were clarified in this theory. The c-axis charge dynamics in an array of the intrinsic Josephson junctions reveals the size dependence when the in-plane (ab-plane) area is decreased. This phenomena is caused by the Coulomb blockade effect. The plasma oscillations in this system become unstable when the in-plane area decreases below some critical value, Wc. The c-axis charge dynamics in the system with an in-plane area less than Wc is dominated by the single Cooper-pair tunneling. I have developed a renormalization group theory for the Coulomb blockade effect in an array of the intrinsic Josephson junctions. The explicit expression for Wc was derived.

在这些体系中，高tc铜酸盐中的CuO2层是高温超导性的主要原因。在高温超导体中，Cu02层之间的耦合非常弱。因此，即使在这些超导体的单晶中，c轴输运现象中也会出现约瑟夫森效应，称为本征约瑟夫森效应。在这个研究项目中，我从理论上研究了高tc超导体中与本征约瑟夫森效应相关的c轴输运性质。我已经为在这些超导体中观察到的约瑟夫森等离子体振荡建立了一个完整的量子理论。该理论阐明了准粒子对等离子体激发的影响。本征约瑟夫森结阵列中的c轴电荷动力学揭示了当面内（ab面）面积减小时电荷大小的依赖性。这种现象是由库仑阻塞效应引起的。当面内面积减小到某个临界值Wc以下时，系统中的等离子体振荡变得不稳定。在面内面积小于Wc的体系中，c轴电荷动力学以单对库珀隧穿为主。我已经开发了一个重整化群论库仑封锁效应在一组本征约瑟夫森结。导出了Wc的显式表达式。