PHENOMENOLOGICAL THEORY OF CUPRATE SUPERCONDUCTIVITY

Reasonably good agreement with the superconducting transition temperat ures of the cuprate high-T(c) superconductors can be obtained on the b asis of an approximate phenomenological theory. In this theory, two cr iteria are used to calculate the superconducting transition temperatur e. One is that the quantum wavelength is of the order of the electron- pair spacing. The other is that a fraction of the normal carriers exis t as Cooper pairs at T(c). The resulting simple equation for T(c) cont ains only two parameters: the normal carrier density and effective mas s. We calculate specific transition temperatures for 12 cuprate superc onductors.