Hole Density Dependence of the Critical Temperature and Coupling Constant in the Cuprate Superconductors

• Published in: Science (American Association for the Advancement of Science) Vol. 249; no. 4973; pp. 1143 - 1146
• Main Authors: M.-H. Whangbo, Torardi, C. C.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 07-09-1990; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: 360204 - Ceramics, Cermets, & Refractories- Physical Properties; Atoms; CHALCOGENIDES; Chemical bonding; Chemical valence; Condensed matter: electronic structure, electrical, magnetic, and optical properties; COPPER COMPOUNDS; Copper oxide superconductors; COPPER OXIDES; CRITICAL TEMPERATURE; Cuprates; DATA; Density; ELECTRIC CONDUCTIVITY; Electric properties; ELECTRICAL PROPERTIES; ELECTRONIC STRUCTURE; Electrons; Exact sciences and technology; EXPERIMENTAL DATA; High temperature superconductivity; INFORMATION; MATERIALS SCIENCE; Mathematical constants; MOLECULAR STRUCTURE; NUMERICAL DATA; OXIDES; Oxygen; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; Physics; SUPERCONDUCTIVITY; Superconductors; Theory and models of superconducting state; THERMODYNAMIC PROPERTIES; TRANSITION ELEMENT COMPOUNDS; TRANSITION TEMPERATURE; Hole; Transition metal Compounds; Cooper pair; Theoretical study; Charge carrier concentration; Superconducting transition; Inorganic compound
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.249.4973.1143

A bond valence sum (BVS) analysis was performed for the p-type cuprate superconductors. The superconducting critical temperature T$_c$ versus in-plane Cu-O BVS correlation for copper is grouped into classes and subclasses. Only within a class or subclass for which the nonelectronic effect is constant does the variation of the in-plane Cu-O BVS reflect the corresponding change in the hole density n$_H$ of the CuO$_2$ layers. This study strongly suggests that the T$_c$ for every class or subclass of the superconductors is an inverted parabolic function of n$_H$, and so is the coupling constant λ for Cooper pair formation.