The Electronic Spectrum of Fullerenes from the Dirac Equation

The electronic spectrum of sheets of graphite (plane honeycomb lattice) folded into regular polihedra is studied. A continuum limit valid for sufficiently large molecules and based on the tight binding approximation is derived. It is found that a Dirac equation describes the flat grafite lattice. Curving the lattice by insertion of odd numbered rings can be mimicked by coupling effective gauge fields. In particular the C60 and related molecules are well described by the Dirac equation on the surface of a sphere coupled to a color monopole sitting at its center. Email: [email protected] 2 On leave from: Instituto de Ciencias de Materiales, CSIC, Cantoblanco, 28050 Madrid, Spain. Address after October 1992: Instituto de F́ısica Fundamental, CSIC, 28006 Madrid, Spain.