Local density of states near the surface of high-Tc superconductors under magnetic field based on the t-J model

Quasiparticle states near the surface of d-wave superconductors in a magnetic field are studied based on the t-J model on the 2D square lattice within the Gutzwiller approximation. We perform a calculation on the local density of states near the (I 10) surface, by changing the hole concentration in the presence of applied magnetic field. In the low-doping region, the zero-energy peak (ZEP) is not sensitive to the applied magnetic field. With the increase of the hole concentration, the ZEP splits into two due to the broken time reversal symmetry state with induced subdominant s-wave like component. Even in this case, the position of split peak is insensitive to the applied magnetic field. (C) 2002 Elsevier Science B.V. All rights reserved.