Metallic and insulating states in two-dimensional C60-polymers

摘要

Variations in the band structures of the two-dimensional C60-polymers arestudied, when pi-conjugation conditions are changed. We investigate therectangular and triangular polymers, in order to discuss metal-insulatortransitions, using a semiempirical model with the Su-Schrieffer-Heeger typeelectron-phonon interactions. We find that electronic structures change amongdirect-gap insulators and the metal, depending on the degree of pi-conjugationsin the rectangular polymer. The triangular polymer changes from the indirectgap insulator to the metal as the pi-conjugations increase. High pressureexperiments could observe such pressure-induced metal-insulator transitions.