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Magnetization plateau and quantum phase transition of the S=1/2 trimerized XXZ spin chain

Kiyomi Okamoto·Atsuhiro Kitazawa
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Abstract

We study the plateau of the magnetization curve at $M = M_{\rm s}/3$ ($M_{\rm s}$ is the saturation magnetization) of the $S=1/2$ trimerized $XXZ$ spin chain. By examining the level crossing of low-lying excitations obtained from the numerical diagonalization, we precisely determine the phase boundary between the plateau state and the no-plateau state on the $Δ-t$ plane, where $Δ$ denotes the $XXZ$ anisotropy and $t$ the magnitude of the trimerization. This quantum phase transition is of the Berezinskii-Kosterlitz-Thouless type.

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Kiyomi Okamoto, Atsuhiro Kitazawa. 1998-09-09. Magnetization plateau and quantum phase transition of the S=1/2 trimerized XXZ spin chain. https://doi.org/10.1088/0305-4470%2F32%2F25%2F304

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