Evidence for Skyrmion crystallization from NMR relaxation experiments
  A resistively detected NMR technique was used to probe the two-dimensional electron gas in a GaAs/AlGaAs quantum well. The spin-lattice relaxation rate $(1/T_{1})$ was extracted at near complete filling of the first Landau level by electrons. The nuclear spin of $^{75}$As is found to relax much more efficiently with $T\to 0$ and when a well developed quantum Hall state with $R_{xx}\simeq 0$ occurs. The data show a remarkable correlation between the nuclear spin relaxation and localization. This suggests that the magnetic ground state near complete filling of the first Landau level may contain a lattice of topological spin texture, i.e. a Skyrmion crystal. 
G. Gervais, H.L. Stormer, D.C. Tsui, P.L. Kuhns, W.G. Moulton, A.P.   Reyes, L.N. Pfeiffer, K. W. Baldwin, and K.W. West