Resonant excitonic emission of a single quantum dot in the Rabi regime

We report on coherent resonant emission of the fundamental exciton state in a single semiconductor GaAs quantum dot. A resonant regime with picosecond laser excitation is realized by embedding the quantum dots in a one-dimensional waveguiding structure. As the pulse intensity is increased, Rabi oscillation is observed up to three periods. The Rabi regime is achieved owing to an enhanced light-matter coupling in the waveguide but with different dynamics with respect to usual cavity quantum electrodynamics. The resonant control of the quantum dot fundamental transition opens new possibilities in quantum state manipulation and quantum optics experiments in condensed-matter physics.

Figure 1

(Color online) Schematic experimental configuration. The $X$ axis is the free axis of the wire and corresponds to the light propagation direction. The embedded QDs are elongated along the $X$ axis. $Y$ is the light polarization direction and $Z$ is the growth axis. The heart-shaped optical mode and the crescentlike quantum wire are represented in gray and blue colors, respectively.

Figure 2

Resonant emission of a single QD at 10 K and low pump power. Inset: time-resolved $\mu \text{PL}$ excited at resonance. The decay time is in this case $T=300\text{ps}$.

Figure 3

(Color online) Rabi oscillations obtained from the integrated resonant luminescence (black dots) as a function of the pulse area and the square root of the laser power. The blue (dark gray) solid line and the red (gray) dashed curve represent the calculated time-integrated population of the level with and without damping parameter, respectively.

Figure 4

(a) $\pi$-pulse shape and occupation probability $P\left(t\right)$ of the excited state. Schematic representation of the frequency dependence of (b) the transparency window, (c) the refractive index, and (d) the dispersion $dn/d\omega$. (e) Schematic spatial compression of the pulse during interaction with the dot (black squares).