Sixteen-state magnetic memory based on the extraordinary Hall effect
  We report on a proof-of-concept study of split-cell magnetic storage in which multi-bit magnetic memory cells are composed of several multilevel ferromagnetic dots with perpendicular magnetic anisotropy. Extraordinary Hall effect is used for reading the data. Feasibility of the approach is supported by realization of four-, eight- and sixteen- state cells. 
A. Segal, M. Karpovski, and A. Gerber
cond-mat.str-el