Acoustic plasmons and cuprate superconductivity

Journal Article · Sun Aug 01 00:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.3455· OSTI ID:6073350

Ishii, Y ^[1]; Ruvalds, J ^[2]

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1. Department of Material Science, Himeji Institute of Technology, Kamigori, Hyogo 678-12 (Japan)
2. Physics Department, Stanford University, Stanford, California 94305 (United States)

The plasmon response is analyzed for a tight-binding model of two energy bands. The majority charge carriers originate from the Cu-O planes with copper orbitals of [ital d][sub [ital x]][sup 2][minus][ital y][sup 2] symmetry hybridized with the oxygen [ital p] states. The second band is more localized and yields low-energy acoustic plasmons that are well defined over a wide momentum range for appropriate positions of the Fermi energy [ital E][sub [ital F]]. The use of bandwidths comparable to band-structure computations for YBa[sub 2]Cu[sub 3]O[sub 7] yields a maximum energy [ital FTHETA][congruent]0.2 eV for the minority hole plasmon, which is a candidate for mediating superconducting pairing of the majority electrons. The transition temperature [ital T][sub [ital c]] is shown to correlate with the prefactor [ital FTHETA] as a function of [ital E][sub [ital F]] in a weak-coupling analysis. If removal of oxygen raises [ital E][sub [ital F]], the corresponding decrease of [ital FTHETA] would be compatible with the observed drop in [ital T][sub [ital c]] for YBa[sub 2]Cu[sub 3]O[sub 7[minus][delta]]. The calculated structure factor reveals narrow acoustic plasmon peaks that should be accessible to electron-loss probes. Threshold structure in the electronic density of states for the narrower band may be related to observed Knight-shift variations.

• DOE Contract Number: FG05-84ER45113
• OSTI ID: 6073350
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:5; ISSN PRBMDO; ISSN 0163-1829
• 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
AMINES
AMMONIUM COMPOUNDS
BAND THEORY
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
CHARGE CARRIERS
COPPER COMPOUNDS
COPPER OXIDES
CUPRATES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
HIGH-TC SUPERCONDUCTORS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLASMONS
QUASI PARTICLES
QUATERNARY COMPOUNDS
SUPERCONDUCTIVITY
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES