SPATIAL TRAJECTORIES OF CONDUCTION ELECTRONS IN A NARROW-GAP SEMICONDUCTOR IN AN EXTERNAL MAGNETIC FIELD

We have derived, from an analysis of the motion of the center of mass of a conduction electron wave packet, the trajectory of a conduction electron in an InSb-like material under the influence of a static magnetic field and a sinusoidal electric field. In addition to the motion of the electron in space, the precession of the electron\u27s intrinsic spin has also been found. These motions have been interpreted in such a way as to give insight into the origins of the electric-dipole-induced spin resonance and the combined resonance. Specifically, it was found that superimposed on the well known cyclotron motion (which leads to the cyclotron resonance), small perturbations exist which are consistent with the type of motion necessary to give rise to the combined and spin resonances. These perturbations are intimately connected with the spin orbit coupling of the electron p states in the valence band. As a further application, the analysis has been extended to include the effects of magnetic lattice ions on the motion of a conduction electron, such as would exist in certain of the class of materials known as Diluted Magnetic Semiconductors. The major modifications which occur in this case are consistent with the quantum mechanical result, and involve an alteration in the effective g-factor. Finally, a preliminary formulation has been outlined for describing the motion of conduction electrons in zero-gap semiconductors