Quasiparticle Bound States around Fractional Vortices in s-wave Superconductor

摘要

We calculate the local density of states (LDOS) around two half quantum vortices in an s-wave superconductor on the basis of the quasiclassical Eilenberger theory to investigate the effect of the phase discontinuity. We show that the LDOS pattern around fractional vortices is qualitatively different from that around a conventional vortex. We find that novel bow-tie-shaped bound states appear in the high energy region, which can be evidence for fractional vortices through scanning tunneling microscopy/spectroscopy. We also show that the system with n fractional vortices with the vorticity 1/n is similar to Josephson junctions.