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arXiv · 1610.03826

Quantum to classical transition in the ground state of a spin-$S$ quantum antiferromagnet

Bimla Danu·Brijesh Kumar
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Abstract

We study a frustrated spin-$S$ staggered-dimer Heisenberg model on square lattice by using the bond-operator representation for quantum spins, and investigate the emergence of classical magnetic order from the quantum mechanical (staggered-dimer singlet) ground state for increasing $S$. Using triplon analysis, we find the critical couplings for this quantum phase transition to scale as $1/S(S+1)$. We extend the triplon analysis to include the effect of quintet dimer-states, which proves to be essential for establishing the classical order (Néel or collinear in the present study) for large $S$, both in the purely Heisenberg case and also in the model with single-ion anisotropy.

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Bimla Danu, Brijesh Kumar. 2017-07-10. Quantum to classical transition in the ground state of a spin-$S$ quantum antiferromagnet. https://doi.org/10.1140/epjb%2Fe2017-70693-7

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