Where are the edge-states near the quantum point contacts? A self-consistent approach

In this work, we calculate the current distribution, in the close vicinity of the quantum point contacts (QPCs), taking into account the Coulomb interaction. In the first step, we calculate the bare confinement potential of a generic QPC and, in the presence of a perpendicular magnetic field, obtain the positions of the incompressible edge states (IES) taking into account electron–electron interaction within the Thomas–Fermi theory of screening. Using a local version of Ohmʹs law, together with a relevant conductivity model, we also calculate the current distribution. We observe that, the imposed external current is confined locally into the incompressible strips. Our calculations demonstrate that, the inclusion of the electron–electron interaction, strongly changes the general picture of the transport through the QPCs.