The spatial behavior of Landau levels (LLs) for the ν = 1 quantum Hall regime at the edge of a wide channel is studied in a self-consistent way by using a generalized local density approximation proposed here. Both exchange interaction and strong electron correlations, due to edge states, are taken into account. They essentially modify the spatial behavior of the occupied lowest spin-up LL in comparison with that of the lowest spin-down LL, which is totally empty. The contrast in the spatial behavior can be attributed to a different effective one-electron lateral confining potentials for the spin-split LLs. Many-body effects on the spatially inhomogeneous spin-splitting are calculated within the screened Hartree-Fock approximation. It is shown that, far from the edges, the maximum activation energy is dominated by the gap between the Fermi level and the bottom of the spin-down LL, because the gap between the Fermi level and the spin-up LL is much larger. In other words, the maximum activation energy in the bulk of the channel corresponds to a highly asymmetric position of the Fermi level within the gap between spin-down and spin-up LLs in the bulk. We have also studied the renormalization of the edge-state group velocity due to electron correlations. The results of the present theory are in line with those suggested and reported by experiments on high quality samples.PACS: 73.20.Dx, 73.40.Hm.
I. INTRODUCTIONEven though most previous theoretical works have developed a noninteracting picture of the edge states in quantum Hall regime, the influence of electron-electron interactions on the edge-state properties in a channel [1-5] and on the subband structure of quantum wires [6][7][8], [4] has been the subject of intense study in the recent years. In Refs. [1,4,7], only the direct Hartree interaction was taken into account. Nevertheless, edge states played no fundamental role in many studies that develop or use theoretical pictures of the spin-splitting Landé g * factor enhanced by the exchange interaction [9][10][11][12][13][14][15][16]. On the other hand, in Ref. [17], correlation effects due to edge states on the effective g * factor for a quantum wire at the ν = 1 quantum Hall regime were considered, while for a wide channel only some qualitative estimation was given. It was shown that correlations, due to the screening at the edges, strongly suppress the exchange splitting and smoothen the energy dispersion at the edges. [17] This paper provides a step further towards the understanding of the role of electron-electron interactions in the ν = 1 quantum Hall effect regime, in particular, the very important role of edge states, by extending the approach of Ref. [17], which was based on the screened Hartree-Fock approximation (SHFA) [9,18,19]. By using the SHFA, we develop a generalized local density approximation (GLDA), which is an essential improvement of the previous modified local density approximation (MLDA) of Ref. [17]. The main objective is to determine the enhanced spinsplitting for the two-dimensional ele...