Ultrafast coherent exciton- and spin-control in quantum wells

Summary form only given. We apply coherent control to manipulate density and spin dynamics of excitons in quantum wells. We contrive complete destruction of photoexcited exciton populations within a few hundred femtoseconds of their creation to induce ultrafast excitonic nonlinearities. This technique combines the strength of resonant with the speed of nonresonant transitions and is, therefore, promising for ultrafast optical devices, which would not suffer from long-lived persistent carrier populations. Coherent spin control allows the switching between different spin populations.