@article{121251,
  author = {D. Reznik and P. Bourges and H. F. Fong and L. P. Regnault and J. Bossy and C. Vettier and D. L. Milius and I.A. Aksay and B. Keimer},
  title = {Direct observation of optical magnons in YBa2Cu3O6.2},
  abstract = { We have used high-energy inelastic neutron scattering to detect optical magnons directly in antiferromagnetic YBa2Cu3O6.2. The optical magnon gap is 67+/-5 meV. This implies an intrabilayer superexchange constant perpendicular to the CuO2 layers of J(perpendicular to) = 0.08 J(parallel to) where J(parallel to) is the in-plane nearest-neighbor superexchange constant. },
  year = {1996},
  journal = {Physical Review B},
  volume = {53},
  pages = {14741-14744},
  month = {06/1996},
  isbn = {0163-1829},
  language = {eng},
}