Effect of Pressure on Superconducting Properties

摘要: It is shown that the existence of superconductivity in a material, and its critical temperature, depends strongly on pressure. Several parameters are pressure-dependent: (1) structure, particularly bond distances, (2) Hubbard U, (3) coupling between sites, (4) orbital occupation number. Eliashberg theory often leads to incorrect predictions, for example A(3)C(60) with A = K, Rb, Cs. While T (C) correctly predicted be higher Rb3C60 than K3C60 decreasing pressure both cases, Cs3C60 not superconducting at ambient The same case pure metals such as Cs Ca (superconducting high pressure). electron pairs, similar Marcus model single electrons, appears agree experiment most cases.