NONBACKSCATTERING CONTRIBUTION TO WEAK-LOCALIZATION

We show that the enhancement of backscattering responsible for the wea k localization is accompanied by a reduction of the scattering in othe r directions. A simple quasiclassical interpretation of this phenomeno n is presented in terms of a small change in the effective differentia l cross section for a single impurity. The reduction of the scattering at the arbitrary angles leads to the decrease of the quantum correcti on to the conductivity. Within the diffusion approximation this decrea se is small, but it should be taken into account in the case of a rela tively strong magnetic field when the diffusion approximation is no lo nger valid.