Exact solution of a periodic-cluster Hubbard model with an electron-lattice interaction

Journal Article · Fri Jul 15 04:00:00 EDT 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.1754· OSTI ID:6988743

Proetto, C R; Falicov, L M

An exact solution of a modified Hubbard model for a tetrahedral cluster with periodic boundary conditions is presented. It includes a static electron-lattice interaction in which the intersite bond-hopping parameter is a function of the bond electron occupation. It is found that the intrasite Coulomb repulsion and the effective attractive electron-lattice interaction have, generally speaking, opposite (although not identical) effects. They cancel each other exactly along a line of singularities in parameter space. The state vectors are easily obtained analytically. A study is made of magnetic and superconducting static correlation functions as functions of the parameters. Various forms of anisotropic superconducting fluctuations are favored in the various regimes. There is an indication of possible states with coexisting nonuniform, nonisotropic superconductivity and antiferromagnetism caused by a ''compromise'' between the competing forces.

• Research Organization: NORDITA, Blegdamsvej 17, DK-2100 Copenhagen OX, Denmark
• OSTI ID: 6988743
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:3; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

656002* -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANALYTICAL SOLUTION
ANISOTROPY
ANTIFERROMAGNETISM
BOUNDARY CONDITIONS
CORRELATION FUNCTIONS
COULOMB FIELD
ELECTRIC CONDUCTIVITY
ELECTRIC FIELDS
ELECTRICAL PROPERTIES
ELECTRON-PHONON COUPLING
ELECTRONIC STRUCTURE
FLUCTUATIONS
FUNCTIONS
MAGNETIC PROPERTIES
MAGNETISM
PHYSICAL PROPERTIES
SOLID CLUSTERS
SUPERCONDUCTIVITY
VARIATIONS