Local spectroscopy of edge channels in the quantum Hall regime with local probe techniques

We present measurements of the tunnelling conductance between edge channels in the quantum Hall regime. By using a local potential perturbation induced by the tip of a scanning force microscope we are able to enhance the tunnelling coupling and map its strength along the edge of the two-dimensional electron gas. It is suggested that the presented method is promising for the local investigation of inter-edge-channel scattering and edge-channel equilibration.