Intrinsic Josephson Junctions and their Terahertz Functions

本征约瑟夫森结及其太赫兹函数

基本信息

批准号：
14350176
负责人：
NAKAJIMA Kensuke
金额：
$ 9.66万
依托单位：
Hirosaki University (2003-2004)Tohoku University (2002)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

High-Tc superconducting cup per oxides (HTSC) show strong anisotropies due to their layered crystal structures consisting of the superconducting CuO_2 layers and the insulating or normal conducting layers in between them. In particular, current transport behaviors across the layers are governed by Josephson weak coupling and are termed the intrinsic Josephson effects. Junction devices fabricated of the HTSC single crystals to use the intrinsic Josephson effects are the intrinsic Josephson junctions (IJJ). The IJJ is the only HTSC Josephson device which can exploit the large energy gaps characteristic of the HTSC and expected to be useful devices operating at very high frequencies up to the terahertz regime. This research project aims to reveals high frequency properties of IJJ to develop superconducting solid state devices for detection and oscillation of terahertz waves. We study (1)precise control of junction properties and (2)effects of externally applied electromagnetic waves on th … More e collective motion of Josephson vortices in the IJJ.For (1), we develop a novel method to control the junction properties by the ion implantation of impurities with strong oxygen affinities.For(2), we succeeded to observe high frequency responses on the vortex flow state which is generated by a flux-flow experiment system designed for this research consisting of a compact cryo-cooler and permanent magnets. By using this system, we found a remarkable zero-crossing step that indicates phase-locking of moving Josephson vortices to the externally applied electromagnetic waves. This results is quite important because it is evident that the electromagnetic waves drives Josephson vortices or vice versa and applicable to amplification and oscillation of terahertz waves by using IJJ. Furthermore, we found periodic potentials introduced in the IJJ along the direction of vortex motion is effective to develop the in-phase coherent motion of the Josephson vortices over the IJJ that is a key point to realize the efficient emission of electromagnetic waves from the IJJ. Less

高-TC超导杯每氧化物（HTSC）由于其分层的晶体结构而表现出强烈的各向异性，这些晶体结构由Josephson wea k coupling和Intrinsic Josephson效应固有的约瑟夫森连接（IJJ）是唯一可以利用HTSC的较大能量差距的HTSC JOSEPHSON设备，并且预计将在非常频率的情况下使用Terahertz的频率。 terahertz波的检测和振荡的设备。通过具有强大氧气亲和力的离子杂质。（2），我们的研究是由紧凑型冷冻剂和永久质量组成的。约瑟夫森（Josephson）涡流的涡流是，结果很明显，这是驱动约瑟夫森（Josephson）沃尔萨（Josephson volsa）的，并且适用于terahertz波的振荡。来自IJJ的电磁波发射。