Two-gap, high temperature superconductor, ARPES data, the pseudogap, and magnetic circular dichroism from the negative-U perspective

Recent photoemission work on underdoped high temperature superconductor cuprates between Tc and T*, the pseudogap temperature, are interpreted within the framework of a previously developed two-subsystem, resonant negative-U scenario. From this exposition, incorporating a developed 2q diagonal striping model, detailed understanding follows of the angle resolved photoemission spectroscopy (ARPES) results together with certain scanning tunnelling microscopy and far-infrared optical data. The origin of the magnetic circular dichroism and related effects shown by such materials below T* is explained