Coherent control of phonon quantum beats
β Scribed by V.M. Axt; M. Herbst; T. Kuhn
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 579 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0749-6036
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β¦ Synopsis
The coherent control of excitons coupled to longitudinal optical phonons is analyzed in the quantum kinetic regime. Different models allowing for different levels of sophistication in the theoretical treatment are compared. Within a simple two-level model of the exciton system analytical results relevant for short-time excitation in the low-density regime are derived, which are nonperturbative with respect to the exciton-phonon interaction. For pulses of finite duration and high intensity, numerical calculations are presented realizing a nonperturbative treatment with respect to both the exciton-phonon as well as the excitonphoton coupling. It is shown that for two-level systems, the use of high intensity pulses opens new possible control scenarios that combine the effects of phase control with Rabi oscillations. These findings are compared with quantum kinetic calculations for a two-band semiconductor model. Here we present results for one, two and three dimensions. Within this model, the coupling to the continuum of states above the band edge provides a dephasing mechanism missing in few-level models. It is shown that also the dephasing properties can be coherently controlled. Furthermore, it is demonstrated that the strength and controllability of phonon beats characteristically depend on the dimension of the system.
π SIMILAR VOLUMES
We consider the effect of the partial coherence ofthe excitation light source on the characteristics of quantum beats in isolated molecules. Using a variant of a phase diffusion model we show that the laser incoherence can induce two distinctly different types of behavior, depending upon the relativ