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Spin Gap in Two-Dimensional Heisenberg Model for CaV$_4$O$_9$

Nobuyuki Katoh·Masatoshi Imada
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Abstract

We investigate the mechanism of spin gap formation in a two-dimensional model relevant to Mott insulators such as CaV$_4$O$_9$. From the perturbation expansion and quantum Monte Carlo calculations, the origin of the spin gap is ascribed to the four-site plaquette singlet in contrast to the dimer gap established in the generalized dimerized Heisenberg model.

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Nobuyuki Katoh, Masatoshi Imada. 1995-10-11. Spin Gap in Two-Dimensional Heisenberg Model for CaV$_4$O$_9$. https://doi.org/10.1143/jpsj.64.4105

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