Effect of magnetic field on the electrostatic screening due to non-equilibrium electrons in the presence of deep repulsive traps

摘要

The problem of electrostatic screening of the perturbation potential due to lattice imperfections by hot electrons has been studied here in the presence of crossed electric and non-quantising magnetic fields and under the condition when the lifetime of the carriers is controlled by deep repulsive trap. The screening characteristics are calculated in the general case of any mechanism of energy and momentum scattering of the hot carriers in the strong and weak magnetic field limits. For some definite scattering mechanisms, however, the characteristics are obtained in the presence of any finite value of the magnetic field. The results calculated for Ge seem to be interesting in that they are not only different from what can be obtained for an ensemble that is in thermodynamic equilibrium with the lattice atoms but are also quite different from what one obtains under the condition when the lifetime of the hot electrons in the presence of the crossed electric and magnetic fields are controlled by attractive traps. It is seen that the presence of the magnetic field sometimes introduces significant changes in the screening characteristics. The limitations of the present theory are explained and its possible applicability is discussed.