Pair breaking of multigap superconductivity under parallel magnetic fields in the electric-field-induced surface metallic state

摘要

The roles of paramagnetic and diamagnetic pair-breaking effects in superconductivity in the electric-fieldinduced surface metallic state are studied using the Bogoliubov–de Gennes equation when magnetic fields are applied parallel to the surface. The multigap states of the subbands are related to the depth dependence and the magnetic field dependence of the superconductivity. In the Fermi-energy density of states and the spin density, subband contributions successively appear from higher-level subbands with increasing magnetic fields. The characteristic magnetic field dependence may be a key feature to identify the multigap structure of the surface superconductivity.