Aragón Sánchez, J., R. Cortés Maldonado, M. I. Dolz, N. R. CejasBolecek, C. J. van der Beek, M. Konczykowski, and Y. Fasano. "Direct visualization of local interaction forces in Bi2Sr2CaCu2O8+Î´ vortex matter." Materials Today: Proceedings 14 (2019): 34–37.
Abstract: We study the local vortexvortex interaction force fi of the structure frozen during a fieldcooling process in an electronirradiated Bi2Sr2CaCu2O8+Î´ sample. We compute this magnitude from snapshots of the vortex structure obtained via magnetic decoration experiments at various fields H in the same sample. Since the observed structures correspond to the equilibrium ones frozen at Tâˆ¼Tirr(H)[1], at this temperature the local modulus of fi roughly equals the local pinning force at the decorated surface of the sample. We estimate the most probable local pinning force from the mode value of the fi(r)distribution, fpm. We found that fpm grows algebraically with H and in electronirradiated samples is 5020% smaller than for samples with columnar defects.

Cejas Bolecek, N. R., M. I. Dolz, A. Kolton, H. Pastoriza, C. Jvander Beek, M. Konczykowski, M. Menghini, G. Nieva, and Y. Fasano. "Geometrical Confinement Effects in Layered Mesoscopic Vortex Matter." Journal of Low Temperature Physics 179, no. 12 (2015): 35–41.
Abstract: We study the geometrical confinement effect in Bi 2 Sr 2 CaCu 2 O 8+Î´ mesoscopic vortex matter with edgetosurface ratio of 7â€“12 %. Samples have inplane square and circular edges, 30 Î¼ m widths, and âˆ¼ 2 Î¼ m thickness. Direct vortex imaging reveals the compact planes of the structure align with the sample edge by introducing topological defects. The defect density is larger for circular than for square edges. Molecular dynamics simulations suggest that this density is not an outofequilibrium property but rather determined by the geometrical confinement.
