MAGNETIC-PROPERTIES OF THE SKYRMION GAS IN 2 DIMENSIONS

The classical ferromagnet is analyzed in two dimensions via a mean-fie ld treatment of the CP1 model valid in the limit of low temperature an d of weak magnetic field. At high skyrmion densities, we find that the magnetization begins to decrease linearly with temperature, but it th en crosses over to a Curie law at higher temperature. The-comparison o f these results with recent Knight-shift experiments on the quantum Ha ll state is fair.