Magnetization plateau of an S=3/2 spin chain with on-site anisotropy

Abstract

We numerically investigate the magnetization plateau at M= M S/3 ( M S is the saturation magnetization) of the S=3/2 spin chain having the isotropic nearest-neighbor spin–spin interactions and also the on-site anisotropy D( S j z ) 2with D>0. When D is varied, we find a no-plateau region ( D< D c1=0.387) and two plateau regions, D c1< D< D c2=0.943 and D c2< D. We explain the physical origin of these plateaus by use of the valence-bond-solid picture.