Screening of Impurities in the Quantum Hall Regime
The equilibrium screening of a single impurity by a two-dimensional electron gas (2DEG) residing on a finite disk in a quantizing perpendicular magnetic field at low temperature is investigated. The electron-electron interaction is included in the Hartree approximation and the impurity is represented by the Coulomb potential of a negatively or positively charged point particle situated in the plain of the 2DEG. We observe how the binding energy of the impurity oscillates with the filling factor of the Landau bands (Lb’s), reflecting the dependence of the screening on the location of the chemical potential with respect to the Landau bands. Implications for the optical properties of the 2DEG are discussed.
KeywordsFilling Factor Coulomb Potential Landau Level Energy Shift Impurity Potential
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