1ST-ORDER QUANTUM CORRECTIONS TO THE CURRENT DRIVEN BY A FORCE AND EINSTEIN EQUIVALENCE

Employing a superposition representation of the density matrix for a fixed energy the first order quantum corrections to the current driven by a weak constant force are calculated for independent charge carriers scattered by uncorrelated point‐like scatterers. This complements a preceding treatment of the corresponding diffusion problem and demonstrates the Einstein equivalence as a property of the density matrix itself. The changes in kinetic energy caused by the force field lead to a reformulation of the correction terms which resemble now the known vertex structure of the Bethe‐Salpeter equation. The influence of the force is considered explicitly in the propagator construction. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA