Interim report on the charge-transfer resonance model for the Cu-O superconductors

Journal Article · Mon May 01 04:00:00 EDT 1989 · IBM Journal of Research and Development; (USA)

DOI:https://doi.org/10.1147/rd.333.0215· OSTI ID:5706601

Varma, C M ^[1]

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1. AT and T Bell Labs., Murray Hill, NJ (USA)

The two-band model including intra-atomic repulsion on Cu and near-neighbor Cu-O repulsion for the high-temperature superconductors is supported by a variety of experiments and theoretical calculations as the minimum necessary. The specific mechanism for high T/sub c/ through charge-transfer resonances was proposed because the known alternative mechanisms - phonons and magnetic excitations - were believed unlikely. The case for charge-transfer-resonance-induced high T/sub c/ has, however, not yet been proven. Equally important, the various anomalies in the metallic state are not yet understood. However, calculations on the model do show a charge-transfer-gap insulating state which is antiferromagnetic at and near 1/2 filling, a metallic state for intermediate filling with effective particle-particle attraction, and a charge-transfer instability beyond a certain filling.

• OSTI ID: 5706601
• Journal Information: IBM Journal of Research and Development; (USA), Journal Name: IBM Journal of Research and Development; (USA) Vol. 33:3; ISSN IBMJA; ISSN 0018-8646
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
656100* -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETISM
CALCULATION METHODS
CHALCOGENIDES
CHARGE EXCHANGE
COPPER COMPOUNDS
COPPER OXIDES
DATA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY GAP
EXPERIMENTAL DATA
HIGH TEMPERATURE
INFORMATION
MAGNETISM
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
PHYSICAL PROPERTIES
SUPERCONDUCTIVITY
SUPERCONDUCTORS
THEORETICAL DATA
TRANSITION ELEMENT COMPOUNDS