Polarized and unpolarized neutron-scattering study of the dynamical spin susceptibility of YBa{sub 2}Cu{sub 3}O{sub 7}
- Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)
- Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)
- Department of Chemical Engineering, Princeton University, Princeton, New Jersey 08544 (United States)
We report an extensive study of magnetic excitations in fully oxygenated YBa{sub 2}Cu{sub 3}O{sub 7}, using neutron scattering with and without spin polarization analysis. By calibrating the measured magnetic intensity against calculated structure factors of optical phonons and against antiferromagnetic spin waves measured in the same crystal after deoxygenation to YBa{sub 2}Cu{sub 3}O{sub 6.2}, we establish an absolute intensity scale for the dynamical spin susceptibility, {chi}{double_prime}({bold q},{omega}). The integrated spectral weight of the sharp magnetic resonance at {h_bar}{omega}=40 meV and {bold q}{sub {parallel}}=({pi}/{ital a},{pi}/{ital a}) in the superconducting state is {integral}{ital d}({h_bar}{omega}){chi}{sub res}{sup {double_prime}}({ital q},{omega})=(0.52{plus_minus}0.1) at low temperatures. The energy and spectral weight of the resonance are measured up to {ital T}=0.8{ital T}{sub {ital c}}. The resonance disappears in the normal state, and a conservative upper limit of 30 states/eV is established for the normal state dynamical susceptibility at {bold q}{sub {parallel}}=({pi}/{ital a},{pi}/{ital a}) and 10 meV{le}{h_bar}{omega}{le}40 meV. Our results are compared to previous neutron-scattering data on YBa{sub 2}Cu{sub 3}O{sub 7}, theoretical interpretations of NMR data and current models of the 40 meV resonance. {copyright} {ital 1996 The American Physical Society.}
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 383263
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 54, Issue 9; Other Information: PBD: Sep 1996
- Country of Publication:
- United States
- Language:
- English
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