Vortex state Doppler shift on local density of states

The hole doped high T-c copper oxides have a d-wave order parameter with li ne nodes in the gap, and the extended quasiparticle states near the nodes a re expected to dominate the bulk density of states at low energy in a magne tic field H. In a semiclassical approach the effect of the vortex cores on these states is accounted for through the Doppler shift associated with the circulating supercurrents and this has lead to a good understanding of the specific heat. The local density of states (LDOS) measured in STM is also affected by the existence of supercurrents. This leads to ridges on the LDO S as a function of energy which are not present in the H = 0 case. The posi tion of the resulting structure in energy and in distance from the vortex c ore is described.