Ajay Kumar Ghosh

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Vortex Line Ordering in the Driven 3-D Vortex
Glass

• Ajay Kumar Ghosh
• Jadavpur University
• Kolkata, India

Peter Olsson Umeå University Umeå, Sweden
Stephen Teitel University of Rochester Rochester,
NY USA
Vortex Wroclaw 2006
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3D Frustrated XY Model
kinetic energy of flowing supercurrents on a
discretized cubic grid
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Equilibrium Behavior
critical pc at low temperature p lt pc
ordered vortex lattice p gt pc
disordered vortex glass
we will be investigating p gt pc
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Resistively-Shunted-Junction Dynamics
apply current density Ix response voltage/le
ngth Vx vortex line drift vy
Units
voltage/length temperature
current density time
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RSJ details
twisted boundary conditions voltage/length new
variable with pbc stochastic equations of motion
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Previous Simulations
Domínguez, Grønbech-Jensen and Bishop - PRL 78,
2644 (1997) vortex density f 1/6, 12 L
24, Jz J?? weak disorder ?? moving Bragg
glass vortex lines very dense, system sizes
small, lines stiff Chen and Hu - PRL 90, 117005
(2003) vortex density f 1/20, L 40, Jz
J????? weak disorder p 1/2 pc moving Bragg
glass with 1st order transition to
smectic single system size, single disorder
realization, based on qualitative analysis of
S(k) Nie, Luo, Chen and Hu - Intl. J. Mod. Phys.
B 18, 2476 (2004) vortex density f 1/20, L
40, Jz J????? strong disorder p 3/2
pc moving Bragg glass with 1st order transition
to smectic single system size, single disorder
realization, based on qualitative analysis of
S(k) We re-examine the nature of the moving
state for strong disorder, p gt pc, using finite
size analysis and averaging over many disorders
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Parameters
ground state p 0
vortex density f 1/12 Jz J???????? p
0.15 gt pc 0.14 L up to 96
Ix Vx
vortex line motion vy
Quantities to Measure
structural
dynamic use measured voltage drops to infer
vortex line displacements