Domain Regime in the 2D Disordered Vortex Matter

The 2D disordered vortex matter is simulated by large-scale molecular dynamics methods at T=0. Performing sweeps with the magnetic field and the disorder, we find a disordered Vortex Glass/Molasses Regime at high fields/disorder, and a Domain Regime at low fields/disorder. We do not find evidence for a region with a dilute gas of dislocations, assumed by some theoretical approaches. In the Domain Regime the dislocations are organized into domains walls, defining large dislocation-free domains. The boundary between these regimes exhibits reentrant behavior as a function of the magnetic field. This boundary is a crossover, characterized by the roughening of the domain walls.