Two-stream instabilities in a semiconductor in the presence of a magnetic field

Carrier wave instabilities in semiconductors having only one type of carriers (electrons) are described. These instabilities are shown to result from a nonuniformity in the electron drift velocity, and to occur only in the presence of a magnetic field. It is also shown that the mechanism that is responsible for the instability is the same whether the magnetic field be transverse or parallel to the direction of electron drift. © 1969 The American Institute of Physics.