Coexistence of Ferromagnetism and Superconductivity in ZrZn2: The dependence of the critical temperature of ZrZn2 on its magnetization

To study ferromagnetic super conductor we used green function formalism important in many particle system especially in superconductivity. We take a model hamiltonian for two band superconductors as we only consider triplet pairing (ESP) which can have two bands one spin up band and the other spin down band. Only spin triplet case was taken because the superconducting state lie only in the ferromgnetic phase hence parallel spin electrons favored to participate in pair formation. Since ferromagnetic state is characterized by magnetization we found expression of superconducting critical temperature for triplet pairing (ESP) interms of the order parameter magnetization. Starting from a model Hamiltonian for a triplet superconductor an expression for the critical temperature has been obtained. We found that coexistence of triplet superconductivity and ferromagnetism is as a possibility and that only the down pairing electrons participate in the pair formation.