Mott Transition, Antiferromagnetism, andd-Wave Superconductivity in Two-Dimensional Organic Conductors

Abstract

We study the Mott transition, antiferromagnetism, and superconductivity in layered organic conductors using the cellular dynamical mean-field theory for the frustrated Hubbard model. A $d$-wave superconducting phase appears between an antiferromagnetic insulator and a metal for $t^{\prime }/t=0.3–0.7$ or between a nonmagnetic Mott insulator (spin liquid) and a metal for $t^{\prime }/t\ge 0.8$, in agreement with experiments on layered organic conductors including $\kappa \mathrm{\text{−}}(\mathrm{ET}{)}_2{\mathrm{Cu}}_2(\mathrm{CN}{)}_3$. These phases are separated by a strong first-order transition. The phase diagram gives much insight into the mechanism for $d$-wave superconductivity. Two predictions are made.