ENTRAINMENT OF CURRENT CARRIERS IN A SUPERLATTICE UPON IONIZATION OF IMPURITY CENTERS BY NONLINEAR ELECTROMAGNETIC-WAVES

The effect of entrainment of carriers is studied in the process of ion ization of impurity centers in a quantum superlattice by nonlinear per iodic electromagnetic waves representing the most general solution of the sine-Gordon equation and expressed in terms of Jacobi elliptic fun ctions. It is shown that the entrainment current vanishes at k = 1 (k is the coefficient of wave nonlinearity). In addition, the entrainment current exhibits a number of extrema caused by the presence of harmon ics with frequencies multiples to the fundamental frequency in the exp ansion of the nonlinear wave in the Fourier series. Numerical calculat ions of the photocurrent are performed in the short-circuit regime for typical parameters of the superlattice. The estimates showed that the entrainment electron current upon ionization of impurities exceeds, u nder certain conditions, the entrainment current of free electrons.