Fig. 1 Effective magnetic dispersions measured by inelastic neutron scattering for: (left) La$_2$CuO$_4$ from Coldea et al. 2001; (middle) La$_{1.95}$Sr$_{0.05}$CuO$_4$ from Goka et al. 2003; (right) La$_{1.875}$Ba$_{0.125}$CuO$_4$ (Tranquada et al 2004). In each case the dispersion is measured about the AF wave vector.
Fig. 2: (a) Plot of incommensurability $\delta$ vs.\ $x$ for La$_{2-x}$Sr$_x$CuO$_4$ (LSCO), from Fujita et al.2002. Insets indicate orientation of incommensurate peaks for $x\lesssim0.055$ (upper left) and for $x\gtrsim0.055$ (lower right). (b) Orientation angle of the incommensurate peaks.