Persistence of the first-order transition lines in mesoscopic Bi2Sr2CaCu2O8 vortex matter with less than hundred vortices

YANINA FASANO

Nanjing

Workshop; Charla invitada, 14th International Workshop on Vortex Matter; 2013

Center for Superconducting Physics and Material, Nanjing University, China

The persistence of the first-order transition line in the phase diagram of mesoscopic Bi2Sr2CaCu2O8 vortex matter is detected down to a system size of less than hundred vortices. Precise and highly-sensitive to bulk currents AC magnetization techniques proved to be mandatory in order to obtain this information. The location of the vortex matter first-order transition lines is not altered by decreasing the sample size down to 20 micrometers. Nevertheless, the onset of irreversible magnetization is affected by increasing the sample surface-to-volume ratio producing a noticeable enlargement of the irreversible vortex region above the second-peak transition.   Work in collaboration with M. Konczykowski,  M.I. Dolz, H. Pastoriza, V. Mosser, and M. Li