Self-consistent Bogoliubov de Gennes theory of the vortex lattice state in a two-dimensional strong type-II superconductor at high magnetic fields

摘要

A self-consistent Bogoliubov deGennes theory of the vortex lattice state in a2D strong type-II superconductor at high magnetic fields reveals a novelquantum mixed state around the semiclassical Hc2, characterized by awell-defined Landau--Bloch band structure in the quasi-particle spectrum andsuppressed order-parameter amplitude, which sharply crossover into thewell-known semiclassical (Helfand-Werthamer) results upon decreasing magneticfield. Application to the 2D superconducting state observed recently on thesurface of the topological insulator Sb2Te3, accounts well for the experimentaldata, revealing a strong type-II superconductor, with unusually low carrierdensity and very small cyclotron mass, which can be realized only in the strongcoupling superconductor limit.