Electronic structure of the vortex lattice of d − , d + i s − , and d x 2 − y 2 + i d xy -wave superconductors

On the basis of the self-consistent Bogoliubov-de Gennes equations and a tight-binding lattice model, we investigate the quasiparticle spectrum of vortex-lattice state in pure d-, mixed $d+is,$ and ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}{+id}_{\mathrm{xy}}$-wave superconductors. For a d-wave case, the local density of states (LDOS) at the vortex core shows a multipeak structure, and the positions of peaks as well as the width of splitting between peaks are sensitively dependent on both the magnetic-field strength and the orientation of the vortex lattice. For the mixed $d+is$- and ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}{+id}_{\mathrm{xy}}$-wave pairing states, we observe a double-peak structure of the local density of states at vortex center, where the two peaks are asymmetrically situated around the Fermi energy. By taking into account the matrix-element effect, the local density of states appears to be qualitatively consistent with the scanning-tunneling-microscopy experimental data.