Nonlinear Thomas-Fermi-Poisson theory of screening for a Hall bar under strong magnetic fields

Low-temperature screening properties of the inhomogeneous two-dimensional electron gas in a Hall bar subjected to a strong perpendicular magnetic field are explored using a self-consitent approach. An external oscillating modulation potential with an amplitude of the order of the cyclotron energy is added to the electron-confining background potential, and the resulting change of the self-consistent potential is investigated as a function of modulation strength, magnetic field, and temperature. The consequences of Landau-level pinning and the interplay of compressible and incompressible regions for the resulting strongly non-linear screening phenomena are explained.