Novel Collective Excitation in Spin Textured Edges of Quantum Hall Systems

We study the electric and magnetic properties of the edge of a two-dimensional electron gas in presence of a magnetic field and at filling factor unity. The existence of a spin textured edge is proved as a function of the Zeeman coupling and of the smoothness of the confining potential. We also calcu-late the low energy excitation of the spin textured phase. We obtain that in addition to the classical edge magnetoplasmons at small wavectors, there is an almost dispersionless excitation, with a finite gap of energy at zero wavevector. This excitation is associated with the broken symmetry of the spin textured edge phase.