Electronic specific heat in high-Tc superconductors

Although the mechanism of high-Tc oxide superconductors is not clear until now, the density of states (DOS) of quasiparticle contains van Hove singularity (VHS) and the symmetry of d-wave pairing are proved by many experiments. In this paper, by using the equation of anisotropic order parameter and the formula of DOS from two-dimensional tight-binding band structure under the model of VHS, we study the specific heat jump at Tc and the temperature behaviors of electronic specific heat at low temperatures. We came to two conclusions. One is that the electronic specific heat exhibits a square-temperature dependence at very low temperature, the other is that the specific heat jump is enhanced by considering VHS at Tc.