Spin-phonon interaction and the EPR linewidth in La2CuO4 and related cuprates

Abstract

The spin-phonon interaction is derived for Cu2+ ions strongly coupled by the Isotropic exchange interaction. It is shown that in a two-dimensional quantum Heisenberg antiferromagnetic this interaction due to its antisymmetric structure couples the phonon modes near the wave vectors (±π/a, ±π/a) to the staggered magnetization. A contribution of the spin-phonon interaction to the EPR linewidth is calculated and its temperature dependence compared with other sources of the broadening. © 1999 Plenum Publishing Corporation.