Nature of the Low Field Transition in the Mixed State of High Temperature Superconductors
We have numerically studied the statics and dynamics of a model three-dimensional vortex lattice at low magnetic fields. For the statics we use a frustrated 3D XY model on a stacked triangular lattice. We model the dynamics as a coupled network of overdamped resistively-shunted Josephson junctions w...
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Main Authors | , |
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Format | Journal Article |
Language | English |
Published |
19.12.1997
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Subjects | |
Online Access | Get full text |
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Summary: | We have numerically studied the statics and dynamics of a model
three-dimensional vortex lattice at low magnetic fields. For the statics we use
a frustrated 3D XY model on a stacked triangular lattice. We model the dynamics
as a coupled network of overdamped resistively-shunted Josephson junctions with
Langevin noise. At low fields, there is a weakly first-order phase transition,
at which the vortex lattice melts into a line liquid. Phase coherence parallel
to the field persists until a sharp crossover, conceivably a phase transition,
near $T_{\ell} > T_m$ which develops at the same temperature as an infinite
vortex tangle. The calculated flux flow resistivity in various geometries near
$T=T_{\ell}$ closely resembles experiment. The local density of field induced
vortices increases sharply near $T_\ell$, corresponding to the experimentally
observed magnetization jump. We discuss the nature of a possible transition or
crossover at $T_\ell$(B) which is distinct from flux lattice melting. |
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DOI: | 10.48550/arxiv.cond-mat/9712246 |