• Title/Summary/Keyword: Josephson vortex

Search Result 15, Processing Time 0.023 seconds

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
    • /
    • v.6 no.1
    • /
    • pp.52-55
    • /
    • 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.

  • PDF

Oscillatory Josephson-Vortex Resistance in Stacks of $Bi_{2}Sr_{2}CaCu_{2}O_{8+x}$ Intrinsic Josephson Junctions

  • Choi Jae-Hyun;Bae Myung-Ho;Lee Hu-Jong;Kim Sang-Jae
    • Progress in Superconductivity
    • /
    • v.7 no.1
    • /
    • pp.17-21
    • /
    • 2005

  • We report the oscillation of the Josephson vortex-flow resistance in the rectangular stacks of $Bi_{2}Sr_{2}CaCu_{2}O_{8+x}$(Bi-2212) intrinsic Josephson junctions (IJJs). Apiece of Bi-2212 single crystal containing a few tens of IJJs was sandwiched between two gold electrodes and fabricated into a rectangular shape with the typical lateral size of about $1.5{\times}10\;{\mu}m^2$, using e-beam lithography and focused ion-beam etching techniques. In a tesla-range magnetic field applied in parallel with the junction planes, the oscillation of the Josephson vortex flow resistance was observed at temperatures near 60 K. The oscillation results from the interplay between the triangular Josephson vortex lattice and the potential barrier at the boundary of a single crystal. The oscillatory magnetoresistance for different bias currents, external magnetic fields, and the tilt-angles provides useful information on the dynamics of the coupled Josephson-vortex lattice system.

  • PDF

Josephson Vortex Dynamics in Tilted Magnetic Fields (경사 자기장 하에서의 조셉슨 볼텍스 동역학)

  • Jin, Yong-Duk;Ki, Dong-Keun;Lee, Hu-Jong
    • Progress in Superconductivity
    • /
    • v.9 no.2
    • /
    • pp.140-145
    • /
    • 2008

  • We report on the Josephson vortex dynamics in $Bi_2Sr_2CaCuO_{8+\delta}$ natural Josephson junctions by c-axis tunneling measurements. Beside the quasiparticle branches in the current-voltage characteristics, a new set of multiple branches, referred to as Josephson-vortex-flow branches (JVFBs), are observed. The JVFBs emerge in an in-plane magnetic field above $H_0\;=\;{\Phi}_0/{\gamma}s^2$ and show highly hysteretic behavior, which can be explained in terms of the recently proposed dynamic-phase-separation model. In this work we examined the effect on the JVFBs by the presence of pancake vortices generated as the external magnetic field was applied slightly tilted from the in-plane direction. JVFBs were found to become larger and prominent with increasing pancake vortex density as the tilt angle increased, which were presumably caused by slowing down of a Josephson vortex lattice in the presence of pancake vortices.

  • PDF