Large copper isotope effect in oxygen depleted YBa{sub 2}Cu{sub 3}O{sub {ital y}}: Importance of Cu-dominated phonon modes in the pairing mechanism
- Morris Research, Inc., 44 Marguerita Road, Kensington, California 94707 (United States)
- Institute of Molecular Physics, Russian Research Center ``Kurchatov Institute,`` Moscow (Russia)
We have measured the copper isotope effect in YBa{sub 2}Cu{sub 3}O{sub {ital y}}. We find a large positive copper-isotope exponent ({alpha}{sub Cu}{approx_equal}0.37) in the underdoped plateau region ({ital y}{approximately}6.6). The exponent decreases to zero (or slightly negative) in the optimally doped region ({ital y}{approximately}6.94). The {alpha}{sub Cu} in YBa{sub 2}Cu{sub 3}O{sub 6.6} is similar to the {alpha}{sub O} (oxygen-isotope exponent) in YBa{sub 2{minus}{ital x}}La{sub {ital x}}Cu{sub 3}O{sub {ital y}} with the same {ital T}{sub {ital c}}. These comparable values of {alpha}{sub Cu} and {alpha}{sub O} show that phonons which involve Cu motion as well as the (high-frequency) modes of the oxygen in the CuO{sub 2} planes are important in the pairing mechanism. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 397595
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 21 Vol. 54; ISSN 0163-1829; ISSN PRBMDO
- Country of Publication:
- United States
- Language:
- English
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