Characteristic energy losses of electrons in a two-dimensional electron gas in a magnetic field

Abstract

The electron energy loss function is calculated in the random phase approximation for a two-dimensional electron gas in a quantizing magnetic field. Local states of electrons at impurity atoms are taken into consideration. The energy losses due to one-particle and collective excitations of two-dimensional electrons are determined. The activation of electrons localized at impurities leads to the emergence of steps on the dependence of loss function on the energy of an incident electron. Cerenkov losses associated with emission of magnetoplasmons appear starting from a threshold velocity of the electron. When the velocity exceeds the threshold value significantly, the losses are due only to spontaneous emission of magnetoplasmons. The corresponding loss function decreases in inverse proportion to the electron velocity.