Self-organized mixed-phase percolation model of high-temperature superconductivity

The traditional theory of superconductivity is based on the effective medium approximation which is suitable for normal metals and their alloys. For high-temperature superconductors (HTSC) the author has developed an entirely different theory, based on percolation of metallic filaments in a semiconductive matrix. The new theory gives excellent explanations for the many anomalous properties of HTSC which cannot be explained by effective medium theories. The filamentary structure is produced by self-organized percolation in an intermediate phase which has a characteristic phase diagram, whose features are quite general and which has been observed not only to describe HTSC, but also the insulator-metal transition in semiconductor impurity bands