Thermodynamic Properties of d_(x²-y²)+id_(xy) Superconductor

In view of the current interest in d_{x^{2}-y^{2}}+id_{xy} superconductors some of their thermodynamic properties have been studied to obtain relevant information for experimental verification. The temperature dependence of the specific heat and superfluid density show marked differences in d_{x^{2}-y^{2}}+id_{xy} state compared to the pure d-wave state. A second order phase transition is observed on lowering the temperature into a d_{x^{2}-y^{2}}+id_{xy} state from the d_{x^{2}-y^{2}} state with the opening up of a gap all over the fermi surface. The thermodynamic quantities in d_{x^{2}-y^{2}}+id_{xy} state are dominated by this gap as in an s-wave superconductor as opposed to the algebraic temperature dependence in pure d-wave states coming from the low energy excitations across the node(s).