Influence of acoustic phonons on the optical control of quantum dots driven by adiabatic rapid passage

The role of phonons for adiabatic rapid passage in semiconductor quantum dots is studied theoretically. While in an ideal system adiabatic rapid passage results in a full inversion of the quantum dot occupation, phonons hamper this behavior drastically. We show that the transitions between the adiabatic states lead to a temperature-dependent decrease of the final exciton occupation. In contrast to the ideal evolution, the phonon-related perturbation induces dependencies on the pulse power and on the sign of the chirp.

Figure 1

(a), (b) Sketch of the temporal evolution of the instantaneous eigenenergies of the dressed states $E_{\pm }$ for (a) a positive chirp $\alpha >0$ and (b) a negative chirp $\alpha <0$. (c) Final occupation of the exciton state as a function of the initial pulse area $\Theta$ and the chirp $\alpha$. Here the coupling to phonons has been neglected.

Figure 2

Final occupation of the exciton state as a function of the initial pulse area $\Theta$ and the chirp $\alpha$ at different temperatures: (a) $T=1$ K, (b) $T=20$ K, and (c) $T=50$ K. The interaction with phonons is included.

Figure 3

Final occupation of the exciton state (a), (b) at $T=1$ K and (c), (d) at $T=20$ K. Left-hand column [(a), (c)]: Occupation as a function of the initial pulse area $\Theta$ for three different values of the chirp $\alpha =-20$, 0, and 20 ps${}^2$. Right-hand column [(b), (d)]: Occupation as a function of the chirp $\alpha$ for three different initial pulse areas $\Theta =2\pi$, $4\pi$, and $6\pi$.