Ultrafast electric field polarization evolution in the excitonic free polarization decay of GaAs

Summary form only given. In the present experiment we examine the free polarization decay in GaAs and show that in general this assumption is inappropriate; even weak biaxial strain leads to sufficient symmetry breaking that the polarization of the emitted field differs from the incident field and leads to changes in the temporal evolution of the so-called quantum beats. Free polarization decay is a phenomenon that occurs when a transient coherent optical field induces a resonant electronic coherence aligned with the field that oscillates at the natural frequency.