Mott Transition from a Spin Liquid to a Fermi Liquid in the Spin-Frustrated Organic Conductor kappa-(ET)2Cu2(CN)3

Abstract

Pressure-temperature phase diagram of the organic Mott insulator $\kappa$-(ET)${}_2$Cu${}_2$(CN)${}_3$, a model system of the spin liquid on triangular lattice, has been investigated by ${}^1$H NMR and resistivity measurements. The spin-liquid phase is persistent before the Mott transition to the metal or superconducting phase under pressure. At the Mott transition, the spin fluctuations are rapidly suppressed and the Fermi-liquid features are observed in the temperature dependence of the spin-lattice relaxation rate and resistivity. The characteristic curvature of Mott boundary in the phase diagram highlights a crucial effect of the spin frustration on the Mott transition.

4 pages, 5 figures

References in corpus (2)

• Comparison of the phase diagram of the half-filled layered organic superconductors with the phase diagram of the RVB theory of the Hubbard-Heisenberg model
• Thermodynamic Relations in Correlated Systems