Pseudogap phenomenon and superconductivity in a magnetic field

We study the effect of a magnetic field on the d-density wave (DDW) in the presence of dx2-y2 superconducting order parameter (DSC) for high-temperature cuprates using a mean-field calculation of the tight binding model. The phase diagrams for the order parameter with doping are discussed. The phase diagram of the field with filling and also the dependence of the critical field (Hc) on the critical temperature (Tc) have been considered. The temperature dependence of the specific heat is also demonstrated. The effect of the field on the DDW order parameter and the superconducting gap are not alike. While the field suppresses the DSC gap, it tends to increase the DDW gap at the same doping. Moreover the gap to Tc ratio increases with the field. The critical field has a power law dependence (Hc-Tc2).