Phonon mode coupling in superconducting LuNi{sub 2}B{sub 2}C
- Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)
- Brookhaven National Laboratory, Upton, New York 11973 (United States)
Recently, Kawano {ital et al.} reported that an interesting phononlike excitation, localized in {ital q} and {omega}, appears below T{sub c} in the superconducting compound YNi{sub 2}B{sub 2}C. This interesting observation led us to perform a series of experiments on the previously studied LuNi{sub 2}B{sub 2}C superconducting compound covering a large range of {ital q} and {omega}. We demonstrate that there is no new excitation and that the lowest lying excitations can be associated with the {Delta}{sub 4}[{xi}00] acoustic and optical phonon branches which exhibit pronounced dips at low temperatures for wave vectors close to the Fermi surface nesting vector, {bold {xi}}{ital {sub m}}, characteristic of these compounds. Above {ital T{sub c}}, as the temperature decreases the frequencies of both modes in the vicinity of {bold {xi}}{ital {sub m}} decrease and there is a shift of intensity from the upper to the lower mode, an effect characteristic of mode coupling. Below {ital T{sub c}}, there is a dramatic decrease in the linewidth of the acoustic mode due to the opening of the superconducting gap. {copyright} {ital 1997} {ital The American Physical Society}
- Research Organization:
- Brookhaven National Laboratory
- DOE Contract Number:
- AC02-76CH00016; W-7405-ENG-82
- OSTI ID:
- 544241
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 14 Vol. 55; ISSN 0163-1829; ISSN PRBMDO
- Country of Publication:
- United States
- Language:
- English
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