ELEMENTS OF MODERN HIGH-TEMPERATURE SUPERCONDUCTIVITY

摘要

Evidence is presented that all high-temperature superconductors: (i) are p-type; (ii) involve holes located outside the host's cuprate-planes: (iii) contain superconducting charge carriers which are Cooper-paired holes; (iv) have holes with a nodeless, s-wave pairing function that is consistent with a gap function of s-wave symmetry; and (v) involve pairing of holes by Coulomb interactions (not by phonons). The p-type superconductivity in YBa_2Cu_3O_7 resides in the BaO layers and is accompanied by n-type normal conductivity in the cuprateplanes. Consequently the linear-in-temperature term observed in the specific heat and the non-zero offset found in the thermal conductivity divided by temperature are explained.