Download presentation
Presentation is loading. Please wait.
1
Ajay Kumar Ghosh Jadavpur University Kolkata, India Vortex Line Ordering in the Driven 3-D Vortex Glass Vortex Wroc ł aw 2006 Stephen Teitel University of Rochester Rochester, NY USA Peter Olsson Umeå University Umeå, Sweden
3
3D Frustrated XY Model kinetic energy of flowing supercurrents on a discretized cubic grid coupling on bond i phase of superconducting wavefunction magnetic vector potential density of magnetic flux quanta = vortex line density piercing plaquette of the cubic grid uniform magnetic field along z direction magnetic field is quenched weakly coupled xy planes constant couplings between xy planes || magnetic field random uncorrelated couplings within xy planes disorder strength p
4
Equilibrium Behavior critical p c at low temperature p < p c ordered vortex lattice p > p c disordered vortex glass we will be investigating p > p c
5
Resistively-Shunted-Junction Dynamics Units current density: time: voltage/length: temperature: apply: current density I x response: voltage/length V x vortex line drift v y
6
twisted boundary conditions voltage/length new variable with pbc stochastic equations of motion RSJ details
7
Previous Simulations Domínguez, Grønbech-Jensen and Bishop - PRL 78, 2644 (1997) vortex density f = 1/6, 12 ≤ L ≤ 24, J z = 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, J z = J weak disorder p ~ 1/2 p c moving Bragg glass with 1 st 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, J z = J strong disorder p ~ 3/2 p c moving Bragg glass with 1 st 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 > p c, using finite size analysis and averaging over many disorders
8
Quantities to Measure structural dynamic use measured voltage drops to infer vortex line displacements Parameters vortex density f = 1/12 J z = J p = 0.15 > p c ~ 0.14 L up to 96 ground state p = 0 I x V x vortex line motion v y
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.