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Universality class of S=1/2 quantum spin ladder system with the four spin exchange

Keigo Hijii·Kiyohide Nomura
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Abstract

We study s=1/2 Heisenberg spin ladder with the four spin exchange. Combining numerical results with the conformal field theory(CFT), we find a phase transition with central charge c=3/2. Since this system has an SU(2) symmetry, we can conclude that this critical theory is described by k=2 SU(2) Wess-Zumino-Witten model with Z$_2$ symmetry breaking.

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Keigo Hijii, Kiyohide Nomura. 2001-11-21. Universality class of S=1/2 quantum spin ladder system with the four spin exchange. https://doi.org/10.1103/physrevb.65.104413

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