Spin-waves in the mid-infrared spectrum of antiferromagnetic YBa2Cu3O6.0
Institut für angewandte Physik, Universität Karlsruhe -
D-76128 Karlsruhe, Germany
2 Institut für Theorie der kondensierten Materie, Universität Karlsruhe, D-76128 Karlsruhe, Germany
Accepted: 16 May 1996
The mid-infrared spin-wave spectrum of antiferromagnetic was determined by infrared transmission and reflection measurements ( at K. Excitation of single magnons of the optical branch was observed at meV. Two further peaks at meV () and meV () both belong to the two-magnon spectrum. Linear spin-wave theory is in good agreement with the measured two-magnon spectrum, and allows to determine the exchange constant J to be about meV, whereas the intrabilayer coupling J12 is approximately 0.5J.
PACS: 74.72.-h – High-Tc cuprates / 74.25.Gz – Superconductivity: Optical properties / 74.25.Ha – Superconductivity: Magnetic properties
© EDP Sciences, 1996