Rabi oscillations in a semiconductor quantum dot: Influence of local fields

The influence of electron-hole dipole-dipole interactions (local fields) on the excitonic Rabi oscillations in an isolated quantum dot (QD) has been theoretically investigated. An analysis for the QD interaction with monochromatic field and ultrashort Gaussian pulse has been performed. On the basis of optical Bloch equations the Rabi oscillation dynamics has been investigated. As a result, the bifurcation and essentially anharmonic regimes in the Rabi oscillations in a QD exposed to the monochromatic field have been predicted. The strong dependence of the period of Rabi oscillations on the QD depolarization has been revealed. For the Gaussian pulse it has been shown that the final state of inversion as a function of the pulse peak strength demonstrates step-like transitions.

Figure 1

Rabi oscillations of the inversion, $\delta =0$: (a) $\xi =0.002$; (b) $\xi =0.2$; (c) $\xi =0.5$; (d) $\xi =1$; (e) $\xi =3$.

Figure 2

Rabi oscillations of the inversion, $\delta =-\Delta \omega$: (a) $\xi =0.2$; (b) $\xi =0.495$; (c) $\xi =0.5001$; (d) $\xi =0.51$; (e) $\xi =0.6$.

Figure 3

Rabi oscillations of the inversion. Influence of the detuning $(\delta =-0.5\Delta \omega ;\xi =0.1502)$.

Figure 4

The period of the Rabi oscillations as a function of the depolarization parameter $\xi$ for $\delta =-\Delta \omega$.

Figure 5

Rabi oscillation dynamics of QD interacting with the Gaussian pulse: $t_0=0.5\tau$, $\tau \Delta \omega =15$. Two different regimes of the inversion: (a) $\xi =1.0$ (solid line), $\xi =1.26$ (dashed line), $\xi =1.51$ (dotted line); (b) $\xi =1.13$ (solid line), $\xi =1.39$ (dashed line), $\xi =1.61$ (dotted line).

Figure 6

The final state of inversion as a function of the peak field strength of the Gaussian pulse defined by parameter $\xi$: (a) undamped system, $\delta =-0.5\Delta \omega$, $\tau \Delta \omega =15$; (b) damped system $({\gamma }_T={\gamma }_L={10}^{-3}\Delta \omega )$, $\delta =\Delta \omega$, $\tau \Delta \omega =15$ (solid line) and $\tau \Delta \omega =30$ (dotted line).