Figure 3
S as a function of H at T = 2.5 K. The black dashed line is the fit of the first S(H) increase with Eq. (1). The blue dotted line is the strong pinning single vortex behavior speculated for the vortices that enter in the twin boundaries using Eq. (1). The green dashed-dotted line is the fit of the decreasing S(H) data with the equation described by the subtraction of the black and blue line. The red solid line is the fit of the second S(H) increase with Eq. (1). In the bottom of the figure, the field intervals relative to the three S(H) portions are identified with different colours. Finally, the black vertical solid line separates the single vortex state from the collective pinning state while the red vertical dashed line, individuated by the Hsp value, separates the elastic regime from the plastic regime in the framework of the collective pinning theory.
