in continuum states is extremely small.

The asymmetry of the cross-correlation measurement can be explained by ionization of the QD following the radiative Auger emission. In a higher shell, the electron has an enhanced tunneling rate out of the QD [@Muller2013]. Following very fast relaxation down to the Fermi-energy, tunneling back into the $s$-shell of the QD takes about 10 times longer, and the QD is ionized for a finite time. We estimate the corresponding tunneling times by modeling the auto- and cross-correlation measurements (see Supplement).

Finally, we perform the first auto-correlation measurement of the radiative Auger emission itself. For this measurement, all the resonance fluorescence is filtered out (Fig. \[fig:crosscorr\](e)). To maximize the count rate of the weak radiative Auger emission, we use a higher Rabi-frequency compared to the cross-correlation measurement ($\Omega_{\text{R}}=5.4\ \text{GHz}$). The auto-correlation measurement is shown in Fig. \[fig:crosscorr\](f). At zero time delay, there is a clear anti-bunching in the $g^{(2)}$-measurement, which proves the single-photon nature of the emission connected to the radiative Auger process. At non-zero time-delay, the onset of Rabi-oscillations in the $s$-to-$s$ transition is visible as a photon bunching of the radiative Auger emission. Both features are well described by our model (see Supplement).

