Theory of light-induced drift of electrons in coupled quantum wells

Publisher Website
Google Scholar
Abstract
A theory of the new effect of light-induced drift (LID) in coupled potential wells is developed on the basis of the density-matrix method. The effect appears when light excites intersubband electronic transitions. LID manifests itself as the photocurrent of the two-dimensional electron gas in the well plane, which depends on coherent electron tunneling between the coupled wells. The theory shows the effect to possess distinctive features such as a characteristic antisymmetric spectral contour consisting of four alternating positive and negative peaks and the change of sign of the LID current with the sign change of the bias normal to the quantum-well plane. The quantitative estimates for GaAs wells show the LID current to be readily detectable.