CHARGED SPIN-TEXTURE EXCITATIONS AND THE HARTREE-FOCK APPROXIMATION IN THE QUANTUM HALL-EFFECT

We develop a Hartree-Fock approach to the charged spin-texture excitations (CSTE's) of the ferromagnetic incompressible ground state, which occurs in the quantum Hall effect at Landau-level filling factor v = 1. The CSTE's are the appropriate generalization of skyrmions to the situation when there is a nonzero Zeeman coupling. We find for Coulomb interactions that the charged spin-texture excitation energies are always smaller than the excitation energies of localized spin 1/2 quasiparticles and quasiholes. However, the amount by which the energy is lowered is quite small for typical experimental situations. The net spin of the CSTE's is always much larger than 1/2, suggesting that adding or removing charge from a filled Landau level rapidly degrades its spin polarization.