We investigate the statistics of photons emitted by tunneling electrons in a single electronic level plasmonic nanojunction. We compute the waiting-time distribution of successive emitted photons $w\left(\tau \right)$. When the cavity damping rate $\kappa$ is larger than the electronic tunneling rate $\mathrm{\Gamma }$, we show that in the photon-antibunching regime, $w\left(\tau \right)$ indicates that the average delay time between two successive photon-emission events is given by $1/\mathrm{\Gamma }$. This is in contrast with the usually considered second-order correlation function of emitted photons, $g^{\left(2\right)}\left(\tau \right)$, which displays the single timescale $1/\kappa$. Our analysis shows a relevant example for which $w\left(\tau \right)$ gives independent information on the photon-emission statistics with respect to $g^{\left(2\right)}\left(\tau \right)$, leading to physical insight into the problem. We discuss how this information can be extracted from experiments even in the presence of a nonperfect photon-detection yield.

• Received 16 July 2021
• Revised 12 November 2021
• Accepted 22 November 2021

DOI:https://doi.org/10.1103/PhysRevB.104.L241403