Classification of Quasi-Two Dimensional Organic Conductors Based on a New Minimal Model

This paper presents a unified theoretical picture of quasi-two-dimensional organic conductors in a new minimal model based on an anisotropic triangular lattice. These materials exhibit abundance of low-temperature physics, where the systematic understanding was lagging behind respective studies. This is ascribed to a variety in the electronic structure stemming from different arrangements of molecules, i.e. polytypes. We provide a way of mapping different polytypes into our minimal model, where a choice of four different band parameters enables the simple relationships among them. The generalized ground state phase diagram of this model on the plane of these band parameters is obtained from the mean-field calculations with on-site and inter-site Coulomb interactions. By associating the actual materials with the results of calculations, their ground state differences are systematically understood.