• 제목/요약/키워드: josephson junction

검색결과 117건 처리시간 0.019초

Pd Shunt저항의 제작 및 동력학특성 조사 (Pd Shunt Resistor for Josephson Junction : Fabrication and Dynamic Simulation)

  • 김규태;남두우;이규원;유광민
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2003년도 학술대회 논문집
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    • pp.143-145
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    • 2003
  • External shunt resistor is used in Nb/AlOx/Nb Josephson junction which is basic component of RSFQ circuit. This is to increase damping and to make the so called 'self-reset' optimized for high speed operation. In this study, we fabricated and investigated sheet resistance of Pd and PdAu thin film, and simulated the inductance effect of the shunt resistor to the Josepshon junction dynamics.

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$Nb/A1O_x/Nb$ 조셉슨 접합에서 저항측정을 이용한 Nb 전극의 침투깊이 측정 (Determination of Penetration Depth of Nb Electrodes in $Nb/A1O_x/Nb$ Josephson Junction by Resistive Method)

  • 김동호;김규태;박종원;황준석;홍현권
    • 한국초전도ㆍ저온공학회논문지
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    • 제4권1호
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    • pp.50-54
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    • 2002
  • Penetration depth of Nb electrodes in $Nb/A1O_x/Nb$ Josephson junctions has been measured by resistive method. For a given applied field, the total flux through the junction is temperature dependent because the penetration depth of Nb electrode varies with temperature. If the total flux equals an integral multiple of the flux quantum at certain temperatures, resistive peaks appear at those temperatures. The penetration depth of Nb can be determined by applying the above condition, The temperature dependence of penetration depth was found to be well described by the two-fluid model.

A Chaos Simulator using Analogue Circuit to Model Josephson Junction

  • Morisue, Mititada;Noguchi, Hiroshi;Kanasugi, Akinori
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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    • pp.849-852
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    • 1993
  • This paper proposes a novel chaos generator using the model of Josephson junction. Constructing an equivalent circuit of Josephson element by using an operational amplifier, we have made a chaos generator. The feature of this generator is to generate several kinds of oscillations as well as chaotic oscillations by only changing a DC bias current to the junction. In this paper, it is described in detail how to construct the circuit and what kind of oscillations is realized in the circuit. The experimental results of oscillation modes are compared with simulation results with a satisfactory agreement.

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고온 초전도 경사형 모서리 접합을 이용한 4단 쉬프트 레지스터의 동작 (Operation of a Single Flux Quantum 4-stage Shift Register Fabricated with High $T_c$ Ramp-edge Junction Technology)

  • 김준호;박종혁;김상협;정구락;강준희;성건용;한택상
    • Progress in Superconductivity
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    • 제3권1호
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    • pp.83-86
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    • 2001
  • We have fabricated a single flux quantum 4-stage shift register with interface-controlled $Y_1$$Ba_2$$Cu_3$$O_{7-x}$(YBCO) Josephson junction. The YBCO Josephson junctions showed RSJ-like current-voltage(I-V) curves at temperatures 45~80K. We tested load and shift operation of shift register with binary data sequences “1000”, “1010”, “1011”, and “1111” at 58K. For all the binary data sequences, the shift register operated successfully. By operating the circuit with proper current pulses, we observed no errors during at least 12 hours operation for all the data sequences.s.

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Novel Interface-engineered Junction Technology for Digital Circuit Applications

  • Yoshida, J.;Katsuno, H.;Inoue, S.;Nagano, T.
    • Progress in Superconductivity
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    • 제3권1호
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    • pp.1-4
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    • 2001
  • Interface-engineered junctions with $YbBa_2$$Cu_3$$O_{7}$ as the counter electrode were demonstrated. The junctions exhibited excellent Josephson characteristics with a Josephson critical current ($I_{c}$) ranging from 0.1 mA to 8 mA and a magnetic field modulation of the $I_{c}$ exceeding 80% at 4.2 K while maintaining complete c-axis orientation of the counter-electrode layer. The$ 1\sigma$ spreads in $I_{c}$ for junctions with an average $I_{c}$ of 1-2 mA were 5-8% for 16 junctions within a chip, and 9.3% for a 100-junction array. Our dI/dV measurements suggest that a theoretical approach taking into account both a highly transparent barrier and the proximity effect is required to fully understand the Junction characteristics.ristics.

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$Nb/A1_2O_3/Nb$ 조셉슨 접합의 임계전류밀도 제어 (Jc control of $Nb/A1_2O_3/Nb$ Josephson junction)

  • 김규태;홍현권;이규원
    • 한국초전도ㆍ저온공학회논문지
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    • 제4권1호
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    • pp.1-3
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    • 2002
  • Single Josephson junctions, which are of cross type, of $50 ${\mu}{\textrm}{m}$ {\times} 50 ${\mu}{\textrm}{m}$$ were fabricated under several oxidation conditions to Investigate controllabilities of critical current density (Jc) with the standard KRISS processes. Considering that the self-field effect suppresses the observed critical current (Ice) at high Jc region, we could reasonably estimate Jc values from I-V observations. The dependence of the obtained Jc as a function of exposure, which is equal to pressure (P) times time (t), was well fitted to a curve of Jc ~ (Pt)-0.34. The maximum Jc value at the controllability margin was found to be 3 kA/cm$^2$with the current equipment set up.