Calculation of the temperature dependent AC susceptibility of superconducting disks

The temperature dependent complex AC susceptibilities of high temperature superconducting disks in perpendicular AC magnetic fields (in absence of DC magnetic field) have been calculated from first principles. The temperature dependent AC susceptibilities for different AC field amplitudes, AC field frequencies, reduced pinning potential, and sample thickness have been derived, which demonstrate many features different from what has been observed in the configuration of infinite long slab or cylinder under a parallel-applied AC field. The results of such a realistic configuration of finite-thickness samples in perpendicular fields can be compared directly to the experimental results.