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Spin Liquid State in an Organic Mott Insulator with Triangular Lattice

Y. Shimizu·K. Miyagawa·K. Kanoda·M. Maesato·G. Saito
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Abstract

$^{1}$H NMR and static susceptibility measurements have been performed in an organic Mott insulator with nearly isotropic triangular lattice, $κ$-(BEDT-TTF)$_{2}$Cu$_{2}$(CN)$_{3}$, which is a model system of frustrated quantum spins. The static susceptibility is described by the spin $S$ = 1/2 antiferromagnetic triangular-lattice Heisenberg model with the exchange constant $J$ $\sim$ 250 K. Regardless of the large magnetic interactions, the $^{1}$H NMR spectra show no indication of long-range magnetic ordering down to 32 mK, which is four-orders of magnitude smaller than $J$. These results suggest that a quantum spin liquid state is realized in the close proximity of the superconducting state appearing under pressure.

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Y. Shimizu, K. Miyagawa, K. Kanoda, M. Maesato, G. Saito. 2003-07-19. Spin Liquid State in an Organic Mott Insulator with Triangular Lattice. https://doi.org/10.1103/physrevlett.91.107001

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