Figure 1

(a) Schematic of experimental setup. (b) QD emission spectrum, recorded with a grating spectrometer under resonant laser excitation as is [solid (black) trace], 20$\times$ magnified [dashed (gray) trace], and on a logarithmic scale [solid (red) trace] to visualize the phonon broadband. (c) QD excitation spectrum. (d) Spectrally integrated intensity of scattered light as a function of time showing flickering (dark blue trace) that is inhibited when an additional weak auxiliary laser is added (light green trace). The black trace was recorded with the auxiliary laser only.Reuse & Permissions

Figure 2

(a) Maps of scattered light intensity as a function of detection frequency (abscissas) and excitation frequency (ordinates) relative to the QD transition frequency, for three values of the Rabi frequency. Each panel was recorded in 200 s. At $\Omega /2\pi =0.13$ GHz the detector count rate was $3\times {10}^5$ s${}^{-1}$ at the input of the Fabry-Perot interferometer. Ddashed lines indicate the location of the eigenfrequencies of the coupled laser/QD system. Inset: The line section $\nu =\omega$ together with the corresponding theoretical curve, obtained from Eq. (2). The faint diagonal lines parallel to the $\nu =\omega$ section are due to the residual transmission at high-order modes of the Fabry-Perot interferometer and satellite modes of the laser. (b) Theoretical maps Eq. (2) corresponding to a radiatively broadened two-level system subject to spectral diffusion. (c) Theoretical maps Eq. (1) representing an ideal, radiatively broadened two-level system. (d) Theoretical maps Eq. (A11) representing a two-level system subject to radiative decay and to pure dephasing at a rate $\gamma$. $\gamma$ is chosen so as to obtain the excitation linewidth in Fig. 1c.Reuse & Permissions

Figure 3

Power spectrum of light scattered by the QD at exact resonance ($\Delta \omega =0$) represented on a linear (left) and a logarithmic (right) ordinate scale, for a range of Rabi frequencies. Each spectrum was recorded in 60 s. The theoretical curve [dashed (red) line] was obtained by numerical evaluation of Eq. (2). The shaded (red) area corresponds to coherently scattered light, which dominates whenever $\Omega \lesssim \kappa$. If pure dephasing had a significant role in the scattering process, a broader feature would always be visible, even when $\Omega \ll \kappa$.Reuse & Permissions

Figure 4

(a) Photon statistics of scattered light for three Rabi frequencies. When $\Omega >\kappa$, Rabi oscillations appear. (b) Plot of the total scattered light intensity [solid (red) trace] and the fraction of coherently scattered light intensity [dashed (red) trace], using the same parameters as in Fig. 3. For comparison the same, but not including spectral diffusion, are plotted in blue. (c) Same as (b), but with a laser detuned by $\Delta \omega /2\pi =1$ GHz. (d) Measurement of mutual phase coherence between the coherently scattered light and a local oscillator (LOSC) by interferometry. (e) Intensity of light at the output of the beam splitter in (d) as a function of the LOSC phase.Reuse & Permissions