Photogenerated carriers in La sub 2 CuO sub 4 , YBa sub 2 Cu sub 3 O(7-delta) and Tl sub 2 Ba sub 2 Ca(1-x)GdxCu sub 2 O sub 8 : Polarizability-induced pairing of polarons

Technical Report · Sun Jan 01 00:00:00 EST 1989

OSTI ID:7057734

Foster, C M; Heeger, A J; Kim, Y H; Stucky, G; Herron, N

Photo-induced absorption measurements have been carried out in the infrared spectral range on Tl{sub 2}Ba{sub 2}Ca(1 - x)Gd(x)Cu{sub 2}O{sub 8}(x = 0.02), YBa{sub 2},Cu{sub 3}O(7 - 6) (delta = 0.75) and Lanthanum Copper Oxide. In all three materials, the observation of infrared active vibrational (IRAV) modes and an associated electronic transition with common intensity and temperature dependence indicate the formation of self-localized polarons as photogenerated carriers. The photo-induced electronic transition deep in the infrared implies a major shift of oscillator strength leading to a large local polarizability in the vicinity of the polaron. The dynamic mass (Md) associated with the distortion around the charge carriers and the associated gap state energy are correlated with T(c) of the superconducting phase of each material. We suggest that the enhanced local polarizability may provide an important mechanism for pairing.

• Research Organization: California Univ., Santa Barbara, CA (USA). Inst. for Polymers and Organic Solids
• OSTI ID: 7057734
• Report Number(s): AD-A-219708/5/XAB; TR--36
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656001 -- Condensed Matter Physics-- Solid-State Plasma
656003 -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTRA
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
CHARGE CARRIERS
CHEMICAL REACTIONS
COPPER COMPOUNDS
COPPER OXIDES
DYNAMICS
ELECTROMAGNETIC RADIATION
ELECTRON PAIRS
ELECTRONS
ELEMENTARY PARTICLES
ENERGY-LEVEL TRANSITIONS
FERMIONS
GADOLINIUM COMPOUNDS
GADOLINIUM OXIDES
INFRARED RADIATION
INFRARED SPECTRA
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LEPTONS
MASS
MATERIALS
MECHANICS
OSCILLATOR STRENGTHS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHYSICAL PROPERTIES
POLARIZATION
POLARONS
QUASI PARTICLES
RADIATIONS
RARE EARTH COMPOUNDS
SEMICONDUCTOR MATERIALS
SPECTRA
SUPERCONDUCTORS
THALLIUM COMPOUNDS
THALLIUM OXIDES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE