The Competition Between Superconductivity And Magnetism In Eufe2(As1􀀀�xpx)2 Superconductor

Abstract

The competition between magnetic ordering and superconducting ordering was studies theoretically in EuFe2(As1ð€€€xPx)2 superconductor. A BCS type model Hamiltonian which accounts for the possible competing energies in the system was developed and solved employing Green’s function formalism. Analytical expressions which realte the superconducting critical temperature and coupling strength, superconducting order parameter and temperature, superconducting critical temperature and magnetic order parameter, magnetic transition temperature and magnetic order parameter were obtained from the retarded Green’s functions of the Hamiltonian. The obtained results clrealy indicated the supression of superconducting order. That is, we observed an exponential supression of superconductin critical temperature with magnetic order parameter. Moreover, we observed a possible coexistence of superconductivity and magnetism in EuFe2(As1ð€€€xPx)2 superconductor. This possible coexistence is a fascinating observation because it gives a clue for the possible mechanism for the high-Tc iron based superconductors becasue superconductivity emerges in a very close proximity of antiferromagnetic ordering in most iron based superconductors.