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arXiv:cond-mat/0204375 · Physical review. B, Condensed matter

Quantum magnetization plateaux of an anisotropic ferrimagnetic spin chain

Tôru Sakai, Kiyomi Okamoto

Published May 16, 2002• 60 citations
arXivHTMLPDF

Abstract

The magnetization curve of the $(S,s)=(1,1/2)$ ferrimagnetic alternating spin chain with single-ion anisotropy D is investigated with the numerical exact diagonalization of finite clusters and size-scaling analyses. The system has a plateau at (1/3) of the saturation moment, which corresponds to the spontaneous magnetization for $D=0.$ Varying D in the 1/3-magnetized ground state under the external field along the axis of D, a quantum phase transition is revealed to occur at the critical value $D/J=1.114\ifmmode\pm\else\textpm\fi{}0.001$ where the plateau vanishes. Except for the critical point, the plateau is always opening, but the mechanism is different between $D<{D}_{c}$ and $D>{D}_{c}.$ The change of mechanisms is an evidence to clarify that the plateau originates from the quantization of magnetization.

DOI
10.1103/physrevb.65.214403

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