ANDERSON LOCALIZATION IN ANISOTROPIC ELECTRONIC SYSTEMS UNDER THE INFLUENCE OF WEAK EXTERNAL ELECTRIC AND MAGNETIC-FIELDS

The self-consistent diagrammatic theory derived by Vollhardt and Wolfe has been phenomenologically extended to treat the influence of small electric and magnetic fields on the Anderson localization in disordered anisotropic systems. The approach describes the combined effect of constant electric and magnetic fields as well as the anisotropy of the material on the metal-insulator phase boundary. Known limiting cases are reproduced. The theory is expected to give a consistent picture of field-dependent transport measurements even in such cases where the disorder is comparatively large (k(F) lambda(0) greater than or similar to 1) and the perturbation theory is inapplicable.