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 anti-Skyrmions are found to be present even at filling factor $\nu =1\mathrm{}$. They may be strongly squeezed by the disorder. We have studied the effect of temperature on Skyrmion density and size.

• Received 7 July 1998

DOI:https://doi.org/10.1103/PhysRevLett.82.406