Fig. 2: Lifetime and correlation measurements of a nanowire quantum dot.

a Exciton lifetime measurement (blue dots) showing the fast radiative decay time of 409 ± 11 ps (fit shown in green), measured under pulsed above-bandgap excitation (excitation laser 730 nm, <3 ps pulse at 76 MHz rate). Also shown, the instrument response function of the setup (red line). b Cross-correlation measurements of the neutral exciton line with the charged exciton line. c Cross-correlation measurements of the neutral exciton line with the neutral biexciton line showing clear bunching, proving cascaded photon emission. Note that the antibunching cannot be resolved due to the lifetime (409 ps) shorter than the time resolution of our setup (500 ps). Correlation measurements are performed with a narrow cw 780 nm excitation laser. See Supplementary Fig. 1 for the full set of correlation measurements.