1998/04/06 by Erik Koch, Olle Gunnarsson, Richard M. Martin
Physics and Astronomy · #cond-mat.str-el
published as Proceedings of the IWEPNM97: Molecular Nanostructures, Eds. H. Kuzmany, J. Fink, M. Mehring, S. Roth, World Scientific, 1998, pp 235-238 · 4 pages LaTeX, 2 eps figures included; additional information available at http://www.mpi-stuttgart.mpg.de/docs/ANDERSEN/fullerene/
arxiv created 1998/04/06 · arxiv updated 2009/11/30
The doped Fullerides can be well described by a Hubbard model, which comprises the partly filled, threefold-degenerate t1u orbital and the on-site Coulomb interaction U. The orbital degeneracy is known to shift the critical ratio Uc/W for the Mott-Hubbard transition towards larger values. This puts the half-filled alkali-doped Fullerides A3 C60 on the metallic side of the transition. Prompted by the recent synthesis of isostructural families of integer-doped Fullerides with different fillings, we investigate how the orbital degeneracy affects the Mott transition at integer fillings different from 3. The calculations are done by fixed-node diffusion Monte Carlo, using a trial function, which permits us to systematically vary the magnetic character of the system.