Variational study of spin-density waves and charge-density waves inC60geometry

Abstract

Recently various studies have been devoted to the spin-density-wave (SDW) stability on a C 60 truncated icosahedron structure described by the Hubbard Hamiltonian. We present a Gutzwiller approach to this problem and also give a description of the charge-density wave (CDW) on the same geometry. The various Gutzwiller terms which are needed are derived in a simple way. Our results on SDW are close to those of other calculations both for the critical U/|β| c ∼3 value beyond which the SDW configuration is more stable (U, intra-atomic correlation energy; β, transfer energy) and for the value of the energy and the magnetic moment of the SDW state. In the U/|β| range studied the excitation energy of the CDW state is almost constant