Translation symmetry broken groundstates near quantum hall edge at ν=2

Edge reconstruction for the 2D electron gas in a magnetic field at ν=2 has been studied by Dempsey, Gelfand, and Halperin[1], who found that when the confining potential is softened the two spin polarized channels spatially separate. Using the time dependent Hartree Fock (TDHF) method we found that the collective excitations of this type of groundstate becomes unstable if we decrease the edge potential's slope beyond certail limit. This analysis is similar to what Franco and Brey[2] did for the ν=1 edge. We found two groundstates, charge density wave(CDW) and spin textured edge(STE). These phases not only have lower energy but also screens the background potential better than than the earlier proposed groundstate[1]. Finally, we study the collective excitations of these phases using TDHF method.

[1] Phys. Rev. Lett.70.3639
[2] Phys. Rev. B 56, 10383