Skyrmions in disordered heterostructures}
  We have investigated the effect of weak disorder on the ground state of a two dimensional electron gas in the quantum Hall regime at filling factors slightly deviating from unity. The skyrmions and antiskyrmions are found to be present even at filling factor $\nu=1$. They may be strongly squeezed by the disorder. We have studied temperature effect on skyrmion density and size. 
A.J. Nederveen and Yuli V. Nazarov