Spin dynamics in cuprate perovskites

• Published in: Физика низких температур
• Date: 2006
• Main Authors: Sherman, A., Schreiber, M.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2006
• Subjects: Spin Models
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/120191
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Spin dynamics in cuprate perovskites / A. Sherman, M. Schreiber // Физика низких температур. — 2006. — Т. 32, № 4-5. — С. 499–504. — Бібліогр.: 23 назв. — англ.

Results obtained with the use of the t–J model of Cu–O planes and Mori’s projection operator
 formalism are compared with data of neutron scattering experiments in lanthanum and yttrium
 cuprates. This comparison allows us to interpret the intensive peak at the antiferromagnetic wave
 vector observed in yttrium cuprates as a manifestation of excitations of localized Cu spins. The
 high-frequency incommensurability detected both in lanthanum and yttrium cuprates is connected
 with the dispersion of these excitations, while the low-frequency incommensurability arises due to
 a dip in the spin-excitation damping at the antiferromagnetic wave vector. For moderate doping
 the dip stems from the weakness of the interaction between the spin excitations and holes near hot
 spots. It is conjectured that the dissimilarity of the susceptibility frequency dependencies in yttrium
 and lanthanum cuprates may be connected with different values of the hole bandwidth and
 damping in these crystals.