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

摘要: 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, observation of active vibrational (IRAV) modes an associated electronic transition with common intensity temperature dependence indicate formation self-localized polarons as photogenerated carriers. The photo-induced deep implies a major shift oscillator strength leading to large local polarizability vicinity polaron. dynamic mass (Md) distortion around charge carriers gap state energy are correlated T(c) superconducting phase each material. We suggest that enhanced may provide important mechanism for pairing.