摘要
In this paper, based on the phonon-exciton mechanism, the superconductivity of yttrium barium copper oxide (YBCO) system is explained. The transition temperature (T_C)'s formula is derived by the extended BCS-Eliashberg theory, i.e. phonon-exciton mechanism and McMillan's energy gap function, and the T_C's expressions is reduced by using the Einstein spectrum. Last, the calculating method of element metal effective phonon spectrum is used to the high T_C cuprate YBCO system by using a crystal average atom approximation model. The theoretical analysis and calculational results show that the superconductivity of high T_C YBCO system maybe described by phonon-exciton model.
In this paper, based on the phonon-exciton mechanism, the superconductivity of yttrium barium copper oxide (YBCO) system is explained. The transition temperature (T_C)'s formula is derived by the extended BCS-Eliashberg theory, i.e. phonon-exciton mechanism and McMillan's energy gap function, and the T_C's expressions is reduced by using the Einstein spectrum. Last, the calculating method of element metal effective phonon spectrum is used to the high T_C cuprate YBCO system by using a crystal average atom approximation model. The theoretical analysis and calculational results show that the superconductivity of high T_C YBCO system maybe described by phonon-exciton model.
基金
ThisworkwassupportedbytheStudyAbroadReturneeFoundationofMinistryofEducation(No.200314).
