Interaction-induced polarization rotation in anisotropic semiconductor quantum wells

It is shown that the ultrafast coherent nonlinear optical effect of interaction-induced polarization rotation can be used to identify and study interaction processes in many-body systems. In the theoretical example presented here, signatures of coherent exciton-exciton interactions are identified in polarization trajectories in Poincaré’s Cartesian complex plane of polarization, which is used to visualize the differential polarization rotation (or, alternatively, the polarization of the reflected light) of femtosecond light pulses in uniaxially strained quantum wells. Interaction processes are found to affect significantly the polarization trajectories, including their symmetry properties.