抄録
Effects of impurities on the diamagnetic susceptibility of bismuth are examined on the basis of two-band model of Wolff. The impurity potential is assumed to be of short range but its strength can be arbitrary. The single impurity problem is first considered and it is shown that an impurity level emerges from the upper conduction (lower valence) band and lies above (below) the center of the band gap, when the strength of the potential exceeds a critical value. Assuming a small concentration of impurities, the modification of single electron density of states is calculated, and used in the evaluation of the correction to the diamagnetic susceptibility. It is shown that the contribution from the bound levels is paramagnetic or diamagnetic, according as the level is emerged from the conduction or valence band, reflecting the specific interband effects associated with the strong spin-orbit interaction. The effective g-factor of the electron spin in the impurity level is also derived.
