Large skyrmions in an quantum well

We report tilted-field magnetotransport measurements of two-dimensional electron systems in a 200-Å-wide (Formula presented) quantum well. We extract the energy gap for the quantum Hall state at Landau-level filling (Formula presented) as a function of the tilt angle. The relatively small effective Landé g factor (Formula presented) of the structure leads to skyrmionic excitations composed of the largest number of spins yet reported (Formula presented) Although consistent with the skyrmion size observed, Hartree-Fock calculations, even after corrections, significantly overestimate the energy gaps over the entire range of our data.