Local-pair superconductivity in very high magnetic fields

Abstract

Superconductivity of narrow-band systems with local, short-range attractive interaction in very high magnetic fields is discussed. By examining the excitation spectra of both type-II superconductors with BCS like interaction and local-pair superconductors with negative-U type interaction, it is concluded that gapless single particle energy spectrum is a characteristic feature of superconductivity in very high magnetic fields.