# Spin-wave Dispersion in Half-doped LaSrNiOJournal Article

Published: Tuesday, January 30, 2007
Citation: Physical Review B, Volume 75, Number 1, Pages 12414

Authors (2 total): D. X. Yao, E. W. Carlson

Abstract: Recent neutron scattering measurements reveal spin and charge ordering in the half-doped nickelate, La$_{3/2}$ Sr$_{1/2}$ NiO$_4$. Many of the features of the magnetic excitations have been explained in terms of the spin waves of diagonal stripes with weak single-ion anisotropy. However, an optical mode dispersing away from the (\pi,\pi) point was not captured by this theory. We show here that this apparent optical mode is a natural consequence of stripe twinning in a diagonal stripe pattern with a magnetic coupling structure which is two-fold symmetric, i.e. one possessing the same spatial rotational symmetry as the ground state. @2007 The American Physical Society, Phys. Rev. B 75, 012414 (2007)