A SIMPLE THEORETICAL-ANALYSIS OF THE EINSTEIN RELATION IN ULTRATHIN FILMS OF BISMUTH UNDER QUANTIZING MAGNETIC-FIELD

The Einstein relation for the diffusivity-mobility ratio is studied in ultrathin films of Bi under magnetic quantization in accordance with McClure-Choi, Cohen, Arbikosov, Lax and parabolic ellipsoidal band mod els in the presence of spin, broadening and temperature, respectively. It appears that the same ratio increases with increasing electron con centration and decreasing film thickness in various manners. The McClu re and Choi model shows this more significantly than the other models. We have also suggested an experimental method of determining the Eins tein relation in degenerate materials having arbitrary dispersion laws . (C) 1997 Elsevier Science Ltd.