Static shielding of an impurity near a surface in the presence of a magnetic field

Abstract

The static shielding of a nonmagnetic impurity embedded in a quantum plasma with a surface is examined. Linear-response theory is assumed for the interaction between the impurity and conduction electrons in a uniform positive jellium background and the response function is calculated in the non-self-consistent Hartree single-particle approximation. A uniform magnetic field is applied in a direction perpendicular to the surface. The unperturbed electron eigenstates which are used are those appropriate to a jellium model with planar boundaries simulated by infinite potential barriers. Two separate cases are considered which correspond to a contact interaction and a screened Coulomb potential between the impurity and conduction electrons. The Friedel-Kohn oscillations which are exhibited in the induced electron-number density are due to the logarithmic singularity in the response function.