• 제목/요약/키워드: intrinsic junctions

검색결과 42건 처리시간 0.017초

Dynamical transition of Josephson vortex lattice in serially stacked ${Bi_2}{Sr_2}{CaCu_2}{O_{8+x}}$ intrinsic Josephson junctions

  • Myung-Ho;Hu-Jong
    • Progress in Superconductivity
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    • 제6권1호
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    • pp.52-55
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    • 2004

  • The inductive coupling theory in serially stacked $Bi_2$$Sr_2$$CaCu_2$$O_{8+x}$ intrinsic Josephson junctions predicts that the lattice structure of the Josephson vortices along the c axis gradually changes from the triangular to the rectangular lattice with increasing the vortex velocity. This lattice transition appears as voltage jumps or sub-branch splitting in the Josephson vortex-flow region of current-voltage characteristics (IVC). We report the IVC in external magnetic fields from 2 to 4 T. The stack, with the lateral size of 1.4${\times}$15 $u\m^2$, was fabricated by using the double-side cleaving technique. The sub-branches in the Josephson vortex-flow region, corresponding to a plasma propagation mode in serially coupled intrinsic Josephson junctions, were also observed in the range of 2∼4T. Switching from one branch to another in Josephson vortex-flow region suggests the structural transition of the moving Josephson vortex lattice.

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Effect of spin-polarized current injection on pair tunneling properties of $Bi_2$$Sr_2$Ca$Cu_2$$O_{8+x}$ intrinsic Josephson junctions

  • Shin, Ho-Seop;Lee, Hu-Jong;Do Bang;Nguyen Khac Mac
    • Progress in Superconductivity
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    • 제5권1호
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    • pp.5-8
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    • 2003

  • We studied the effect of spin injection on tunneling conduction properties of intrinsic Josephson junctions formed in $Bi_2$$Sr_2$$CaCu_2$$O_{ 8＋x}$ single crystals. properties of an identical stack (10${\times}$5.0${\times}$0.030 $\mu\textrm{m}^3$) of intrinsic Josephson junctions were compared for the bias current injected through Au and Co electrodes. The suppression of the superconducting gap in the $_2$ double layers and the interlayer Josephson critical current was manifested in the tunneling current-voltage characteristics of the stacks. This effect appears to be caused by the pair breaking associated with spin-polarized carriers injected from the Co electrode into the $Bi_2$$Sr_2$$_2$O$CaCu_{ 8＋x}$ single crystal. This study may provide valuable information on clarifying the mechanism of high- $T_{c}$ superconductivity.y.y.

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Bi$_2Sr_2CaCu_2O_{8+{\delta}}$ Intrinsic 조셉슨 접합의 자기장 효과 (Magnetic field behavior of Bi$_2CaCu_2O_{8+{\delta}}$ Intrinsic Josephson Junctions)

  • 이주형;이헌주;정연욱;이수연;김정구
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 1999년도 High Temperature Superconductivity Vol.IX
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    • pp.178-184
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    • 1999

  • We have measured I-V characteristics of Bi$_2Sr_2CaCu_2O_{8+{\delta}}$ mesa containing a small number of intrinsic stacked Josephson junctions in a magnetic field. We fabricated mesa with an area of 40${\times}$40 ${\mu}$m$^2$ containing 3${\sim}$20 intrinsic junctions. We applied magnetic field perpendicular to He CuO$_2$ planes up to 5T. We observed flux-flow branches and flux-flow steps in the I-V characteristics which might be due to collective motion of Josephson vortices in the long junction limit. In a parallel field, critical current I$_c$ varies as I$_c$(B) ${\sim}$ exp(-B/B$_0$), where B$_0$ is about 2T, which is consistent with the theoretical model. DC and AC intrinsic Josephson effects are also discussed.

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