On the screening of impurities by a two dimensional electron gas in high magnetic fields
We consider the effective potential of an impurity charge placed into a two dimensional non-interacting electron gas at zero temperature and in the presence of a perpendicular, quantum limit magnetic field. Restricting ourselves to a one band model and describing the electronic self-energy due to the impurity scattering in the generalized Born approximation (GBA), it is possible to derive a selfconsistency equation for the RPA-dielectric function.
It is shown that the selfconsistent effective potential can approximately be described by the dimensionless screening parameter sol (k is the magnetic length). Numerical results are presented for sok as a function of the filling factor v at fixed values of the electron concentration and the magnetic field, respectively. The effective potential in real space is depicted for several values of sOP, representative for the situation met in experiments performed at fixed fields.
KeywordsDielectric Function Filling Factor Effective Potential High Magnetic Field Vertex Correction
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