1 research outputs found
Electron correlation effects in a wide channel from the quantum Hall edge states
The spatial behavior of Landau levels (LLs) for the 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.Comment: 9 pages, 4 figure