A calculation of the motion is given for an electron in a simple band subjected to perpendicular magnetic and electric fields. It is shown that the cyclotron resonance frequency is unaffected by the presence of the electric field. For degenerate bands, however, there is a Stark shift of the cyclotron transitions between the low-lying "quantum" states. Calculations using second-order perturbation theory indicate that fractional line shifts of $\frac{\Delta \nu }{{\nu }_0}\sim 10\%$ may be obtained under reasonable experimental conditions. This effect may be useful in the study of the valence bands of germanium and silicon.

• Received 24 November 1958

DOI:https://doi.org/10.1103/PhysRev.114.411