Structure and parameters of boundary vortices in a superconducting Josephson medium

The dynamics of the formation of different-scale vortices and antivortices in bulk and film YBa$_2$Cu$_3$O$_{7-x}$ samples in the process of their “decomposition” into twins with an increase in the field has been demonstrated. The spatial sizes and energies of the revealed twin boundary vortices and antivortices have been determined. It has been shown that the transverse dimensions of twin boundary antivortices coincide with the spatial dimensions of twins. These antivortices keep their shape and decrease with increasing field, becoming smaller than Abrikosov vortices. At any stage of the decomposition of a sample, the transverse dimensions of twin boundary vortices are smaller than the dimensions of twin boundary antivortices and the energy of twin boundary vortices is higher than the energy of twin boundary antivortices.