| Project/Area Number |
12450135
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
電子デバイス・機器工学
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| Research Institution | Tohoku University |
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Principal Investigator |
YAMASHITA Tsutomu Tohoku University, New Industry Creation Hatchery Center, Professor, 未来科学技術共同研究センター, 教授 (30006259)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUGAKI Yoshinao Tohoku University, Research Inst. of Electrical Comm., Research Associate, 電気通信研究所, 助手 (30280887)
CHEN Jian Tohoku University, Research Inst. of Electrical Comm., Associate Professor, 電気通信研究所, 助教授 (90241588)
NAKAJIMA Kensuke Tohoku University, Research Inst. of Electrical Comm., Associate Professor, 電気通信研究所, 助教授 (70198084)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥14,500,000 (Direct Cost: ¥14,500,000)
Fiscal Year 2001: ¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 2000: ¥8,300,000 (Direct Cost: ¥8,300,000)
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| Keywords | 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 |
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| Research Abstract |
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.
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