High Pressure RTSC-Hydrides are Extreme Hard Type-II Superconductors

Abstract

It is argued that most of the RTSC hydrides are intrinsic hard type-II superconductors with strong pinning effects. The pinning centers are long columnar-like defects, with the radius of the order of the superconducting coherence length. The core and electromagnetic pinning are both equally operative, thus giving maximal pinning potential when vortices are oriented along the columnar axis. The theory predicts: (i) large critical currents, (ii) huge decrease of the temperature broadening of the resistance in magnetic field compared with standard superconductors, (iii) large magnetization hysteresis, (iv) the magnetic irreversible line is pushed toward the second critical field and magnetization relaxation is much slower. That the RTSC-hydrides are hard type-II SC can give rise to new physics in these materials.