Period Doubling and Strange Attractors in Quantum Wells

A realistic model of a doped quantum well heterostructure exhibits a subharmonic signal in the presence of intense far-infrared radiation. Nonlinearity enters the model through the effective potential due to the density of electrons in the well. Dephasing and energy relaxation are introduced through a simple density matrix approach. The resultant dynamics show the period-doubling routes to chaos, in the form of strange attractors. All material parameters used are well within the present capabilities of present quantum well technology, and the driving field amplitudes and frequencies are easily obtainable with a free electron laser.