Electronic Raman-scattering study of low-energy excitations in single and double CuO{sub 2}-layer Tl-Ba-(Ca)-Cu-O superconductors

Journal Article · Sat Nov 01 04:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.R11427· OSTI ID:544967

Kang, M ^[1]; Blumberg, G ^[1]; Klein, M V ^[1]; Kolesnikov, N N ^[2]

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1. Department of Physics and Science and Technology Center for Superconductivity, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)
2. Institute for Solid State Physics, Russian Academy of Science, Chernogolovka, Moscow Region, 142 432 (Russia)

The low-energy Raman continuum and the redistribution of the continuum to a peak (the {open_quotes}2{Delta} peak{close_quotes}) in the superconducting state have been studied in Tl-Ba-(Ca)-Cu-O superconductors with a single CuO{sub 2} layer (Tl-2201) and a double CuO{sub 2} layer (Tl-2212). The 2{Delta}/k{sub B}T{sub c} ratios in A{sub 1g} and B{sub 1g} symmetries are larger for Tl-2212 than for Tl-2201. The B{sub 1g}/A{sub 1g} gap ratio is also larger in Tl-2212. The A{sub 1g} intensities of the continuum and the 2{Delta} peak are significantly weaker than the B{sub 1g} intensities in Tl-2201, but are comparable in Tl-2212. This shows that the Coulomb screening is much stronger in Tl-2201. The change from Tl-2201 to Tl-2212 of the normalized A{sub 1g} 2{Delta} peak intensity is identical within experimental error to that of the normalized A{sub 1g} continuum intensity. This suggests that the excitations forming the 2{Delta} peak and the continuum couple to light by the same mechanism. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 544967
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 18 Vol. 56; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CALCIUM OXIDES
COPPER OXIDES
ELECTRONIC STRUCTURE
ENERGY GAP
EXCITATION
HIGH-TC SUPERCONDUCTORS
RAMAN SPECTRA
THALLIUM OXIDES