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Fabrication of THz-Band Generator Utilizing High-Temperature Josephson Superlattice

利用高温约瑟夫森超晶格制造太赫兹波段发生器

基本信息

批准号：
10555116
负责人：
OYA Ginichiro
金额：
$ 8万
依托单位：
Utsunomiya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
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

The purpose of this study is to fabricate a tunable GHz-THz generator working at high temperatures on an experimental basis, which utilizes natural superlattices of intrinsic Josephson junctions, which consist of superconducting CuOィイD22ィエD2 and insulating BiO/SrO layers, in layered high-temperature oxide-superconductor BiィイD22ィエD2SrィイD22ィエD2CaCuィイD22ィエD2OィイD2yィエD2 single crystals.The results obtained in this study are as follows :1. A system for operating and measuring the generator has been prepared using a refrigerator, which can cool it down to 4.2K from 300K.2. Rectangular mesas (superlattices) as generators have been fabricated on an experimental basis from the single crystals (with transition temperatures of 〜 85K), by using photolithography and ion etching.3. The mesas have shown that on their operations, the coherent motion of flux quanta (Josephson vortices) occurs at high rates of (1-5) ×10ィイD1-6ィエD1m/s in them at 4.2K, which correspond nearly to the highest phase velocity of electromagnetic waves induced in the constituent intrinsic Josephson junctions, while at 77K, it occurs at similar high rates in the mesas with less than 20 intrinsic Josephson junctions but at much lower rates in those with more junctions.4. The mesas have shown that the frequencies of oscillations, which take place due to the motion of flux quanta at the high rates in them, can be controlled to linearly with external magnetic fields, and then an oscillation of 80GHz occurs with a magnetic field of 0.16T.5. The mesas have shown that the coherent motion of electronic (hole) waves in the intrinsic Josephson junction superlattices can be excited and controlled by current pulses, so as to generate high frequency oscillations of several ten GHz-THz.

本研究的目的是在实验的基础上制作一个可调谐的高温GHz-THz发生器，它利用自然超晶格的本征约瑟夫森结，其中包括超导CuO层D22和绝缘层BiO/SrO，在层状高温氧化物超导体Bi_（10）D_22_（10）D_2Sr_（10）D_22_（10）D_2CaCu_（10）D_22_（10）D_2O_（10）D_2y_（10）D_2单晶中，一个系统的操作和测量发生器已经准备好使用制冷机，它可以冷却到4.2K从300 K。在实验的基础上，利用光刻和离子刻蚀的方法，从单晶（相变温度为1085 K）中制备了矩形台面（超晶格）作为发电机.台面已经表明，在它们的操作中，通量量子的相干运动在4.2K时，约瑟夫森涡旋以（1-5）×10 ~（-1）× 1它在具有少于20个本征约瑟夫森结的台面中以类似的高速率发生，但在具有更多结的台面中以低得多的速率发生。台面已经表明，振荡的频率，这是由于在他们的高速率的磁通量量子的运动发生，可以控制到线性与外部磁场，然后80 GHz的振荡与0.16T.5的磁场发生。实验结果表明，本征约瑟夫森结超晶格中的电子（空穴）波的相干运动可以被电流脉冲激发和控制，从而产生几十GHz ~ THz的高频振荡。