ENHANCEMENT OF THE G-FACTOR AND SPIN-DENSITY-WAVE STATE IN A CONFINED2DEG IN THE QUANTUM HALL REGIME

We investigate the spin splitting of the Landau bands (LB's) in a conf ined two-dimensional electron gas (2DEG) using the Hartree-Fock approx imation (HFA) for the mutual Coulomb interaction of the electrons. The exchange term of the interaction causes a large splitting of the spin levels of a LB whenever the chemical potential lies between them. The se oscillations of the splitting with the filling factor of the LB's a re conveniently interpreted as an oscillating enhancement of the effec tive g-factor, g. The reduction of g* when a LB is becoming completel y filled is accompanied by a spontaneous formation of a static spin-de nsity wave state whose details depend on the system size and temperatu re.