Checkerboard-like bound states around a vortex in high-Tc cuprate superconductors

We have studied the bound states around a single vortex in high-Tc cuprate superconductors, using the Bogoliubov-de Gennes equation. Experimentally, the bound states around the vortex in high-Tc cuprate superconductors are very different from those in the conventional superconductors. There are no peaks in the local density of states (LDOS) around the Fermi energy and the bound states shows checkerboard-like oscillations. These feature can not be explained in the frameworks of the theory of d-wave superconductivity(dSC). Therefore, we study the effect of pseudogap states, which coexist with d-wave superconductivity. We have adopted the d-wave spin-density-wave(dSDW) theory for the pseudogap state. After deriving the Bogoliubov-de Gennes equation for dSDW+dSC, we have solved it numerically, and obtained the LDOS, which shows bound states with checkerboard-like oscillations. This result shows that the dSDW states is a good candidate for the pseudogap state.