Susceptibility of Superconductors via Scattering Approach

The measurement of magnetic properties of superconductors is usually understood in context with flux penetration length and in case of type-II superconductors also with vortex matter. We investigate the behavior of superconductors in very weak magnetic fields, typically μ0H < 1 μT, near the critical temperature. The aim is to explore the details of SN transition and phase diagram (B,T) of vortex matter in extreme type-II superconductors like cuprates. The data recorded on HTS, even if extensively challenged with theory, are hard to understand as a vortex matter behavior. On the other hand, interpretation on the basis of electron conductivity arising from electron scattering is consistent even with data obtained by x-ray diffraction, photoemission, tunnelling spectroscopy and specific heat.