Superconductivity in the background of disordered flux state of spins

Abstract The phase diagram of the copper oxide materials with the antiferromagnetic and the superconducting properties as a function of doping δ is obtained in the framework of the t - J model by using the Schwinger boson-slave fermion theory. The results show that the spiral order of spins competes and coexists with superconductivity for small doping δ. For large doping δ, superconductivity appears, which may be caused by the occurrence of a disordered flux state of spins. The phase diagram suggests a strong relationship between antiferromagnetism and superconductivity.