<研究ノート>有機三角格子スピン系EtMe[3]Sb [Pd(dmit)[2]][2]における量子スピン液体

Abstract

The family of layered organic salts X[Pd(dmit)[2]][2] are Mott insulators and form scalene-triangular spin-1/2 systems. Among them, EtMe[3]Sb[Pd(dmit)[2]][2] has a nearly regular-triangular lattice. We have investigated the spin state of this salt by [13]C-NMR and static susceptibility measurements. The temperature dependence of the susceptibility is described as that of a regular-triangular antiferromagnetic spin-1/2 system with an exchange interaction J=220-250 K. The [13]C-NMR measurements reveal that the ground state of this system is a spin liquid state, which has gapless excitation at least down to 1.37 K.