Dephasing suppression of excitons in semiconductors

Duncan G. Steel, H. Wang

南不二雄, F. Minami

南不二雄, F. Minami

T.E. Kishimoto, H. Takahashi, Atsushi Hasegawa +2 more

Reuble Mathew, Eric Dilcher, Angela Gamouras +5 more

We demonstrate adiabatic rapid passage on a subpicosecond time scale in a single semiconductor quantum dot, enabling the exploration of a regime of strong (and rapidly varying) Rabi energies for optical control of excitons. An observed dependence of the exciton inversion efficiency on the sign of the pulse chirp demonstrates the dominance of phonon-mediated dephasing, which is suppressed for positive chirp at low temperature. Our findings will support the realization of dynamical decoupling strategies and suggest that multiphonon emission and/or non-Markovian effects should be taken into account.

Salvatore Savasta, Omar Di Stefano, R. Girlanda

We show that the exciton–exciton scattering continuum has a significant influence on the transient non-linear optical response of semiconductor microcavities. Comparison between transient shifts observed in pump and probe experiments and calculations demonstrates almost complete cancellation between mean-field and two-exciton continuum contributions. Moreover, we show that suppression of non-linear absorption of the lower polariton observed in many experiments is determined by the specific spectral shape of these correlations. In particular, we find that the pump induced dephasing of polariton resonances is proportional to the spectrum of four-particle correlations calculated at the energy sum of the pumped and probed polaritons.