Electronic correlation effects on the properties of an half-filled octahedron cluster in a magnetic field
Laboratoire de Physique des Solides, bâtiment 510, Université Paris-Sud, 91405 Orsay, France
Corresponding author: a email@example.com
Revised: 28 July 2000
Published online: 15 March 2001
The present study focuses on electronic correlation effects on magnetic energy, the spin-spin correlation function of an octahedron cluster in the (3, 3) electronic configuration threaded by a magnetic field. Some other spin configurations are also discussed and various field directions are considered. An accurate diagonalisation technique has been used to solve the Hubbard Hamiltonian. A result is analysed on a linear energy stabilisation at low magnetic flux. Moreover, two types of antiferromagnetic transition versus the flux occurring for a correlation term larger than a critical one have been observed, i.e. the likelihood of a charge excitation before the antiferromagnetic transition. Finally, a comparison between the results obtained from the exact diagonalisation and the Gutzwiller method has been carried out, leading to a suggested modification of the Gutzwiller approach in order to improve it.
PACS: 36.40.-c – Atomic and molecular clusters / 36.40.Cg – Electronic and magnetic properties of clusters / 36.20.Kd – Electronic structure and spectra
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001