Energy and number of particles in skyrmion excitations with odd filling of the Landau levels of a two-dimensional electron gas

It is shown that approximations employing projections of wave functions onto a single Landau level are inadequate for describing skyrmion-type excitations. Nonprojected functions give a clear physical picture and calculations are greatly simplified by their use. The expression for the energy of skyrmion excitations differs substantially from the expressions obtained in the approximation of globally projected functions by a series of terms which have a very simple meaning. (C) 1997 American Institute of Physics.