| Project/Area Number |
62550274
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
電子機器工学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
NAKAJIMA Koji Tohoku University, 電気通信研究所, 助教授 (60125622)
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| Co-Investigator(Kenkyū-buntansha) |
OYA Gin-ichiro Tohoku University, 電気通信研究所, 助教授 (00006280)
SAWADA Yasuji Tohoku University, 電気通信研究所, 教授 (80028133)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Superconductivity / Josephson junction / Digital device / Fluxon / Soliton / Josephson sampler / 位相量子 / 量子 / 反量子ソリトン / 〓束量子挿入ゲート / 量子論理回路 / ソリトンロジック |
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| Research Abstract |
We have succeeded in the first direct observation of soliton-antisoliton total interaction in solid state (Josephson junctions). By precise control of the collision point of a fluxon and an antifluxon in a Josephson transmission line (JTL), the several head-on collision processes were directly measured not only in time but also in space by use of a Josephson sampling system where a single sampling head was coupled to the center of the JTL. Depending upon the line bias current for the JTL, annihilation, passing through, and fluxon-anti-fluxon pair creation were observed after collisions. These characteristics were also shown in the numerical analysis for the accelerated JTL with energy dissipation. the interaction area between a fluxon and an antifluxon is about 100 m 250 m in space, and 50ps 120ps in time. We have experimentally observed phase shifts of solitons in the passing through process after collisions. The phase shifts were negative contrary to the analytic solution for the sine-Gordon equation where the phase shift of solitons after interaction is positive. The numerical analysis for the accelerated JTL with energy dissipation also showed a negative phase shift. We also presented experimental results on elementary phase-mode Josephson circuits whose combinations enable us to construct a total data processing system which is expected to be superior to the ordinary voltage-mode Josephson computer in several respects. By using the fabricated elementary circuits composed of SQUIDs and two types of branching points we have experimentally confirmed AND, FAN-OUT, FAN-IN operations, and etc. We have also proposed an INHIBIT circuit, and presented the experimental results on the INHIBIT circuit.
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