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arXiv · 0906.2288

Spin-liquid and magnetic phases in the anisotropic triangular lattice: the case of $\kappa$-(ET)$_2$X

Luca F. Tocchio·Alberto Parola·Claudius Gros·Federico Becca
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Abstract

The two-dimensional Hubbard model on the anisotropic triangular lattice, with two different hopping amplitudes $t$ and $t^\prime$, is relevant to describe the low-energy physics of $\kappa$-(ET)$_2$X, a family of organic salts. The ground-state properties of this model are studied by using Monte Carlo techniques, on the basis of a recent definition of backflow correlations for strongly-correlated lattice systems. The results show that there is no magnetic order for reasonably large values of the electron-electron interaction $U$ and frustrating ratio $t^\prime/t = 0.85$, suitable to describe the non-magnetic compound with X=Cu$_2$(CN)$_3$. On the contrary, N\'eel order takes place for weaker frustrations, i.e., $t^\prime/t \sim 0.4 \div 0.6$, suitable for materials with X=Cu$_2$(SCN)$_2$, Cu[N(CN)$_2$]Cl, or Cu[N(CN)$_2$]Br.

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Luca F. Tocchio, Alberto Parola, Claudius Gros, Federico Becca. 2009-06-12. Spin-liquid and magnetic phases in the anisotropic triangular lattice: the case of $\kappa$-(ET)$_2$X. https://doi.org/10.1103/physrevb.80.064419

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