Physical review. B, Condensed matter
Intersubband optical bistability induced by resonant tunneling in an asymmetric double quantum well
Mark I. Stockman, Lakshmi N. Pandey, Leonid S. Muratov, Thomas F. George
Abstract
An intrinsic optical bistability in a double quantum well is described theoretically. The effect is based on the resonant tunneling of electrons against the electric-field force (the counterfield electron transfer) and is driven and controlled by far-ir radiation exciting an intersubband transition. The theory relies on the density-matrix technique and takes into account optical intersubband excitation, interwell tunneling, the relaxation of populations and polarizations, and the mean-field effects of the transferred electron charge (shifts of the levels and changes of matrix elements). Hysteresis-type curves are obtained for both the charge-transfer probability and the optical absorption as functions of the light intensity. The theory shows the effect to be readily observable under realistic conditions, with the exciting-light intensity as low as 50 W/${\mathrm{cm}}^{2}$.