Magnetic character of the two-dimensional electron gas

The energies of the paramagnetic and ferromagnetic states of the two-dimensional electron gas are evaluated and compared in order to determine the magnetic character of the ground state. The calculations are made with the self-consistent Hartree-Fock approximation and the deformable jellium model. Several transition points between different magnetic phases are obtained. At very high densities of r(s) approximate to 2 a first transition is obtained from a paramagnetic fluid to a ferromagnetic one. At r(st1) approximate to 4.8 a symmetry and magnetic transition is obtained from a ferromagnetic fluid to a paramagnetic localized state with a periodic density centered on a hexagonal lattice. A ferromagnetic localized state is predicted at lower densities. The results are compared with those reported for the system with square symmetry. (C) 2001 Elsevier Science Ltd. All rights reserved.