Edge excitations in the 2D electron gas 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. In this project we study the collective excitations both in the bulk and the edge at ν=2 using the time dependent hartree fock ( TDHF) method. We find that beyond a certain slope of the edge potential both the spin-wave and the charged excitations have instabilities. This analysis is similar to what Franco and Brey[2] did for the ν=1 edge, where they showed that there are other phases (spin textured and charge density wave) with lower energy than the earlier proposed stripe phase by Chamon and Wen[3]. Finally, we will look for translation-symmetry-breaking ground states with lower energy than the one proposed in ref. 1 using Hartree-Fock methods.

[1] Jed Dempsey, B. Y. Gelfand, and B. I. Halperin,Phys. Rev. Lett.70.3639 (1993)
[2] M. Franco and L. Brey,Phys. Rev. B 56, 10383 (1997)
[3] C. de C. Chamon and X. G. Wen, Phys. Rev. B 49, 8227 (1994)