We have investigated the Mott transition in a quasi-two-dimensional Mott insulator EtMe3P[Pd(dmit)2]2 with a spin-frustrated triangular lattice in hydrostatic pressure and magnetic field. In the pressure-temperature (P-T) phase diagram, a valence bond solid phase is found to neighbor the superconductor and metal phases at low temperatures. The profile of the phase diagram is common to those of Mott insulators with antiferromagnetic order. In contrast to the antiferromagnetic Mott insulators, the resistivity in the metallic phase exhibits anomalous temperature dependence, ρ=ρ0+AT2.5.
@article{arxiv.cond-mat/0612545,
title = {Mott Transition in a Valence Bond Solid Insulator with a Triangular Lattice},
author = {Yasuhiro Shimizu and Hikota Akimoto and Hiroyuki Tsujii and Akiko Tajima and Reizo Kato},
journal= {arXiv preprint arXiv:cond-mat/0612545},
year = {2009}
}