Quasiparticles of d-wave superconductors in finite magnetic fields

We study quasiparticles in the d-wave vortex lattice by self-consistently solving the Bogoliubov-de Gennes equations. It is found for a pure d(x2-y2) slate that: (i) Low-energy quasiparticle bands in the magnetic Brillouin zone have a rather large dispersion even in small magnetic fields, indicating the absence of bound states for an isolated vortex; (ii) in finite fields with k(F)xi(0) small, the calculated tunneling conductance at the vortex core acquires a double-peak structure near zero bias as the field is increased from H-c1. We also fmd that mixing of a d(xy)-wave or an a-wave component, if any, develops gradually without transitions as the held grows, having little effect on the funneling spectra.