Pure emitter dephasing: A resource for advanced solid-state single-photon sources

We have computed the spectrum emitted spontaneously by a quantum dot coupled to an arbitrarily detuned single mode cavity, taking into account pure dephasing processes. We show that if the emitter is incoherent, the cavity can efficiently emit photons with its own spectral characteristics. This effect opens unique opportunities for the development of devices exploiting both cavity quantum electrodynamic effects and pure dephasing, such as wavelength-stabilized single-photon sources robust against spectral diffusion.

Figure 1

(a) System under study. (b) Equivalent system in the incoherent-emitter regime: two connected boxes exchanging a quantum of energy.

Figure 2

(Color online) Spectrum $S_{cav}$ emitted by the coupled cavity (red solid line) and spectra emitted by the QD, $S_{QD}^0$ (blue dotted line), and by the cavity, $S_{cav}^0$ (black dashed line), if they were uncoupled for $g=35\mu \text{eV}$, $\kappa =85\mu \text{eV}$, and $\gamma =1\mu \text{eV}$ [(a) and (b)] in the resonant case and [(c) and (d)] in the case $\delta =1\text{meV}$. [(a) and (c)] ${\gamma }^{\ast }=0$; [(b) and (d)] ${\gamma }^{\ast }=0.5\text{meV}$.

Figure 3

(Color online) Efficiency $P_{cav}$ as a function of (a) the pure dephasing rate ${\gamma }^{\ast }$ (b) the QD-cavity detuning $\delta$. Black plots: $g=35\mu \text{eV}$, $\kappa =85\mu \text{eV}$, and $\gamma =1\mu \text{eV}$ (parameters of Ref. [6] and Fig. 2). Red plots: $g=76\mu \text{eV}$, $\kappa =100\mu \text{eV}$, and $\gamma =1\mu \text{eV}$ (parameters of Ref. [8]). (a) Dashed line: $\delta =0$; solid line: $\delta =1\text{meV}$. (b) Dash-dotted line: ${\gamma }^{\ast }=0$; solid line: ${\gamma }^{\ast }=0.5\text{meV}$.