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arXiv · 1904.09629

Spin-$S$ designer hamiltonians and the square lattice $S=1$ Haldane nematic

Nisheeta Desai·Ribhu K. Kaul
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Abstract

We introduce a strategy to write down lattice models of spin rotational symmetric Hamiltonians with arbitrary spin-$S$ that are Marshall positive and can be simulated efficiently using world line Monte Carlo methods. As an application of our approach we consider a square lattice $S=1$ model for which we design a $3\times 3$ - spin plaquette interaction. By numerical simulations we establish that our model realizes a novel "Haldane nematic" phase that breaks lattice rotational symmetry by the spontaneous formation of Haldane chains, while preserving spin rotations, time reversal and lattice translations. By supplementing our model with a two-spin Heisenberg interaction, we present a study of the transition between N\'eel and Haldane nematic phase, which we find to be of first order.

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Nisheeta Desai, Ribhu K. Kaul. 2019-04-21. Spin-$S$ designer hamiltonians and the square lattice $S=1$ Haldane nematic. https://doi.org/10.1103/physrevlett.123.107202

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