EDGE RECONSTRUCTION AND EDGE MELTING OF THE 2-DIMENSIONAL WIGNER CRYSTAL IN A STRONG MAGNETIC-FIELD

The properties of the edge of a two-dimensional electron crystal in a strong magnetic field are studied in the Hartree-Fock approximation. It is demonstrated that the electrons may suffer edge reconstructions or melt at the edge, depending on the strength and nature of the potential which confines the electron system. The melting transition is signaled by the appearance of a mode in the collective excitation spectrum which is gapless even in the presence of pinning centers and is localized at the edge of the system. We argue that an edge melting transition would be accompanied by a qualitative change in the transport properties of the system.