The cooperative dynamical Jahn-Teller effect in alkali doped fullerides

Abstract

The cooperative dynamical Jahn-Teller (JT) effect on a two-dimensional lattice of alkali doped fullerides is considered. It is shown that the C603− anions in the fulleride crystal may be subject locally to the E⊗e JT effect. The ground state of the layer composed of the JT centers is stabilized by coherent electronic and pseudorotational nuclear motion of molecules. The antiferromagnetic ordering of vibronic angular momenta on neighbouring JT centers causes “rotating-meshing-gears”-like dynamics of the lattice, where chains of dimers and a lattice of tetramers are successively formed. It is concluded that the cooperative dynamical JT effect of such a form may provide a fundamental mechanism for the theoretical description of superconductivity of these compounds.