Correlated electrons in high-temperature superconductors

Journal Article · Fri Jul 01 04:00:00 EDT 1994 · Reviews of Modern Physics; (United States)

DOI:https://doi.org/10.1103/RevModPhys.66.763· OSTI ID:7071529

Dagotto, E ^[1]

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1. Department of Physics, National High Magnetic Field Laboratory, MARTECH, Florida State University, Tallahassee, Florida 32306 (United States)

Theoretical ideas and experimental results concerning high-temperature superconductors are reviewed. Special emphasis is given to calculations performed with the help of computers applied to models of strongly correlated electrons proposed to describe the two-dimensional CuO[sub 2] planes. The review also includes results using several analytical techniques. The one- and three-band Hubbard models and the [ital t]-[ital J] model are discussed, and their behavior compared against experiments when available. The author found, among the conclusions of the review, that some experimentally observed unusual properties of the cuprates have a natural explanation through Hubbard-like models. In particular, abnormal features like the mid-infrared band of the optical conductivity [sigma]([omega]), the new states observed in the gap in photoemission experiments, the behavior of the spin correlations with doping, and the presence of phase separation in the copper oxide superconductors may be explained, at least in part, by these models. Finally, the existence of superconductivity in Hubbard-like models is analyzed. Some aspects of the recently proposed ideas to describe the cuprates as having a [ital d][sub [ital x]][sup 2-][ital y][sup 2] superconducting condensate at low temperatures are discussed. Numerical results favor this scenario over others. It is concluded that computational techniques provide a useful, unbiased tool for studying the difficult regime where electrons are strongly interacting, and that considerable progress can be achieved by comparing numerical results against analytical predictions for the properties of these models. Future directions of the active field of computational studies of correlated electrons are briefly discussed.

• OSTI ID: 7071529
• Journal Information: Reviews of Modern Physics; (United States), Journal Name: Reviews of Modern Physics; (United States) Vol. 66:3; ISSN RMPHAT; ISSN 0034-6861
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
ANTIFERROMAGNETIC MATERIALS
BARIUM COMPOUNDS
CALCULATION METHODS
CERIUM COMPOUNDS
CHALCOGENIDES
COMPUTER CALCULATIONS
COPPER COMPOUNDS
COPPER OXIDES
CORRELATIONS
CRYSTAL MODELS
CUPRATES
DIAGRAMS
ELECTRON CORRELATION
ELECTRON SPECTROSCOPY
EMISSION
HIGH-TC SUPERCONDUCTORS
HOLES
HUBBARD MODEL
LANTHANUM COMPOUNDS
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MATERIALS
MATHEMATICAL MODELS
MONTE CARLO METHOD
NEODYMIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHOTOEMISSION
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SECONDARY EMISSION
SPECTROSCOPY
STRONTIUM COMPOUNDS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS