RF-Field-Driven Superconducting Quantum Interference Devices

射频场驱动超导量子干涉装置

• 批准号: 12450135
• 负责人: YAMASHITA Tsutomu
• 金额: $ 9.28万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12450135/
• 关键词: radio-frequency; field-driven; SQUID; Josephson junction; zero-crossing steps; voltagestandards; flux quantum; 磁束量子; 粒界ジョセフソン接合; コプレーナ型共振器; スイッチング素子; A; D変換器; バイクリスタル基板; YBCO薄膜; radio-frequency; field-driven; SQUID; Josephson junction; zero-crossing steps; voltagestandards; flux quantum; 磁束量子; 粒界ジョセフソン接合; コプレーナ型共振器; スイッチング素子; A; D変換器; バイクリスタル基板; YBCO薄膜

The purpose of this study is to investigate the properties of RF-field-driven DC-SQUID (RFDS) in both simulation and experiments for future possible applications. In simulation, we have obtained the dependence of device properties upon (i) frequency of the signal, (ii) power of the signal, (iii) offset DC field, and (iv) operation margins and power gain. Next we fabricated a DC-SQUID using YBa_2Cu_3O_<7-δ> grain boundary Josephson junctions (YBCO-GBJJs) integrated with an H-shaped antenna. The results agreed with numerical ones at low power region. According to these results, we developed a coplanar-type resonator to apply RF signal to a superconducting quantum interference device (SQUID) magnetically. We fabricated a DC-SQUID using YBCO-GBJJs again, and mounted it on the resonator. By applying SF signal of 20GHz to the resonator, we observed Shapiro steps on ;the current-voltage characteristics of the SQUID. The dependence of Shapiro steps upon DC offset field agreed with the numerical results. In comparison with our previous device, the new method has three benefits: 1. We can design a resonator and a SQUID independently. 2. Hence, we can utilize wide-band frequencies by changing the resonator. 3. Also we can utilize the same SQUID for wide-band frequencies, which means we can systematically investigate the dependence of the device properties upon the frequency. Finally we extended the device configuration from two-junction SQUID to three-junction SQUID. Analytical and numerical results showed that the three-junction SQUID would generate a zero-crossing Shapiro step by applying multi-phase RF signals. Hence, the extended RF-Field-Driven SQUID would be applicable to programmable Josephson voltage standards.

这项研究的目的是研究RF场驱动的DC-SQUID（RFD）在模拟和实验中的未来应用中的性质。在仿真中，我们获得了设备属性对（i）信号频率，（ii）信号的功率，（iii）偏移DC场以及（iv）操作余量和功率增益的依赖性。接下来，我们使用YBA_2CU_3O__3O_ <7-udu_x>晶粒边界制造了DC-SQUID JOSEPHSON连接（YBCO-GBJJS），该连接（YBCO-GBJJS）与H形天线集成在一起。结果与低功率区域的数值一致。根据这些结果，我们开发了一个共面型谐振器，将RF信号应用于超导量子干扰装置（Squid）。我们再次使用YBCO-GBJJS制造了DC-Stquid，并将其安装在谐振器上。通过将20GHz的SF信号应用于谐振器，我们观察到了Shapiro的步骤。鱿鱼的电流特性。 Shapiro对DC偏移场的依赖性与数值结果一致。与我们以前的设备相比，新方法具有三个好处：1。我们可以独立设计谐振器和鱿鱼。 2。因此，我们可以利用相同的鱿鱼来实现宽波段频率，这意味着我们可以系统地研究设备属性对频率的依赖性。最后，我们将设备的配置从两连接鱿鱼扩展到三结鱿鱼。分析和数值结果表明，三结鱿鱼将通过应用多相RF信号来产生零交叉的shapiro步骤。因此，扩展的RF场驱动的鱿鱼将适用于可编程的约瑟夫森电压标准。