Magnetic Excitations and Their Energy Change Available to Superconducting Condensation in Optimally Doped YBa₂Cu₃O_6.95

Journal Article · Sun Jan 01 00:00:00 EST 2006 · Nature Physics

DOI:https://doi.org/10.1038/nphys394· OSTI ID:1003369

Woo, H. ^[1]; Dai, Pengcheng ^[2]; Hayden, S M. ^[3]; Mook, Jr, Herbert A ^[2]; Scalapino, D. J. ^[4]; Perring, T. G. ^[5]; Dogan, F. ^[6]

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1. University of Tennessee, Knoxville (UTK)
2. ORNL
3. University of Bristol, UK
4. University of California, Santa Barbara
5. ISIS Facility, Rutherford Appleton Laboratory
6. University of Washington, Seattle

Understanding the magnetic excitations in high-temperature (high-T{sub c}) copper-oxide superconductors is important because they may mediate the electron pairing for superconductivity. By determining the wavevector (Q) and energy ({h_bar}{omega}) dependence of the magnetic excitations, it is possible to calculate the change in the exchange energy available to the superconducting condensation energy. For the high-T{sub c} superconductor YBa{sub 2}Cu{sub 3}O{sub 6+x}, the most prominent feature in the magnetic excitations is the resonance. Suggestions that the resonance contributes a major part of the superconducting condensation have not gained acceptance because the resonance is only a small portion of the total magnetic scattering. Here, we report an extensive mapping of magnetic excitations for YBa{sub 2}Cu{sub 3}O{sub 6.95} (T{sub c} {approx} 93 K). Absolute intensity measurements of the full spectra allow us to estimate the change in the magnetic exchange energy between the normal and superconducting states, which is about 15 times larger than the superconducting condensation energy - more than enough to provide the driving force for high-T{sub c} superconductivity in YBa{sub 2}Cu{sub 3}O{sub 6.95}.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1003369
• Journal Information: Nature Physics, Vol. 2, Issue 9; ISSN 1745--2473
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
YTTRIUM OXIDES
BARIUM OXIDES
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
MAGNETIC PROPERTIES
EXCITATION
PHASE TRANSFORMATIONS
RESONANCE
SCATTERING