https://doi.org/10.1007/s100510070129
Compressibility crossover and quantum opening of a gap for two-dimensional disordered clusters with Coulomb repulsion
1
CEA, Service de Physique de l'État Condensé, Centre d'Études de Saclay, 91191 Gif-sur-Yvette, France
2
Laboratoire de Physique QuantiqueUMR C5626 du CNRS, Université Paul Sabatier, 31062 Toulouse,
France
Received:
13
March
2000
Published online: 15 October 2000
Using Hartree-Fock orbitals with residual Coulomb repulsion,
we study spinless fermions in a two-dimensional random potential.
When we increase the system size L at fixed particle density, the
size dependence of the average inverse compressibility exhibits a
smooth crossover from a 
towards a 1/L decay when the
Coulomb energy to Fermi energy ratio rs increases from 0 to 3.
In contrast, the distribution of the first energy excitation displays
a sharp Poisson-Wigner-like transition at 
.
PACS: 71.30.+h – Metal-insulator transitions and other electronic transitions / 72.15.Rn – Localization effects (Anderson or weak localization)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000
