Doping dependence of the thermopower of high-[ital T][sub [ital c]] cuprates: Tight-binding band model
- Fundamental Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba 305 (Japan)
Tight-binding calculatoins are performed which include both Cu-O and O-O interactions in the CuO[sub 2] plane. These calculations reconcile inconsistencies in observed behaviors of the thermopower [ital S] and the Hall coefficient [ital R][sub [ital H]]: the sign of [ital S] of high-[ital T][sub [ital c]] cuprates at room temperature becomes negative in the overdoped regime, while [ital R][sub [ital H]] remains positive. A striking feature of the CuO[sub 2] antibonding band is that a holelike Fermi surface is formed even when the band is less than half-filled. This brings about an unusual electron state in which the Hall (cyclotron) mass parallel to the Fermi surface is holelike ([lt]0) but the transport mass perpendicular to it is [ital electronlike] ([gt]0). This electronlike transport mass contributes to negative [ital S], while the holelike Hall mass results in positive [ital R][sub [ital H]]. In such a state, the electron on the Fermi surface has complete duality: it is holelike in one direction, but electronlike in another. In the overdoped regime, where [ital R][sub [ital H]][gt]0 and [ital S][lt]0, the hole doping increases the carrier concentration defined as [proportional to] [ital R][sub [ital H]][sup [minus]1], but it decreases the carrier concentration defined as ([ital n]/[ital m][sup *])[sub [ital D]] in Drude's formula. This qualitatively explains the recent muon-spin-rotation ([mu]SR) results that the superconducting carrier concentration [ital n][sub [ital s]]/[ital m][sup *][similar to]([ital n]/[ital m][sup *])[sub [ital D]] decreases with hole doping in the overdoped regime.
- OSTI ID:
- 6715796
- Journal Information:
- Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:5; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
COPPER COMPOUNDS
CRYSTAL DOPING
CUPRATES
ELECTRICAL PROPERTIES
ELECTRON MOBILITY
HALL EFFECT
HIGH-TC SUPERCONDUCTORS
HOLE MOBILITY
MOBILITY
OXYGEN COMPOUNDS
PARTICLE MOBILITY
PHYSICAL PROPERTIES
SUPERCONDUCTORS
THERMOELECTRIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSPORT THEORY