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arXiv · 1209.1928

Spin-liquid versus spiral-order phases in the anisotropic triangular lattice

Luca F. Tocchio·Hélène Feldner·Federico Becca·Roser Valentí·Claudius Gros
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Abstract

We study the competition between magnetic and spin-liquid phases in the Hubbard model on the anisotropic triangular lattice, which is described by two hopping parameters t and t' in different spatial directions and is relevant for layered organic charge-transfer salts. By using a variational approach that includes spiral magnetic order, we provide solid evidence that a spin-liquid phase is stabilized in the strongly-correlated regime and close to the isotropic limit t'/t=1. Otherwise, a magnetically ordered spiral state is found, connecting the (collinear) Néel and the (coplanar) 120° phases. The pitch vector of the spiral phase obtained from the unrestricted Hartree-Fock approximation is substantially renormalized in presence of electronic correlations, and the Néel phase is stabilized in a wide regime of the phase diagram, i.e., for t'/t < 0.75. We discuss these results in the context of organic charge-transfer salts.

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Luca F. Tocchio, Hélène Feldner, Federico Becca, Roser Valentí, Claudius Gros. 2013-01-31. Spin-liquid versus spiral-order phases in the anisotropic triangular lattice. https://doi.org/10.1103/physrevb.87.035143

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