From valence bond solid to unconventional superconductivity in the organic charge-transfer solids

摘要

We show that superconductivity is absent within the 1/2-filled bandtriangular lattice repulsive Hubbard model that has been proposed for organiccharge-transfer solids. We posit that organic superconductivity is ratherreached from a Bond-Charge Density Wave that either constitutes the insulatingstate proximate to superconductivity, or is extremely close in energy to theantiferromagnetic state, and replaces the latter under pressure. TheBond-Charge Density Wave can be described within an effective attractive $U$extended Hubbard Hamiltonian with repulsive nearest neighbor interaction $V$. Afirst-order transition from the insulating to the superconducting state occurswithin the model with increasing frustration.