Influence of pure dephasing on emission spectra from single photon sources

We investigate the light-matter interaction of a quantum dot with the electromagnetic field in a lossy microcavity and calculate emission spectra for nonzero detuning and dephasing. It is found that dephasing shifts the intensity of the emission peaks for nonzero detuning. We investigate the characteristics of this intensity shifting effect and offer it as an explanation for the nonvanishing emission peaks at the cavity frequency found in recent experimental work.

Figure 1

(Color online) Left: Schematic displaying the energy levels of the two-level QD and cavity. $\mid e⟩$ and $\mid g⟩$ denote the excited and ground state of the emitter and ∣1⟩ and ∣0⟩ denote the excited and empty cavity mode. Right: Schematic of a micropillar with a QD in a high-$Q$ cavity. Light escapes from the cavity in the forward direction at a rate $\kappa$, while the QD excitation decays at rate $\gamma$.

Figure 2

(Color online) $S_C$ (full) and $S_E$ (dashed) for (a) zero dephasing and (b) $5\mathrm{GHz}$ dephasing rate. The emitter $\left({\omega }_0\right)$ and cavity $\left({\omega }_c\right)$ frequencies are indicated with the dashed lines, and the total emission intensity $\int d\Omega (S_C+S_E)$ is constant for all detunings. Parameters: $g_0=8\mathrm{GHz}$, $\kappa =1.6\mathrm{GHz}$, and $\gamma =0.32\mathrm{GHz}$.

Figure 3

(Color online) (a) Relative left peak (cavity peak) intensity in $S_C$ as a function of detuning $\Delta$. (b) Relative cavity emission intensity as a function of dephasing rate ${\gamma }_p$. Parameters: $g_0=8\mathrm{GHz}$, $\kappa =1.6\mathrm{GHz}$, $\gamma =0.32\mathrm{GHz}$.

Figure 4

(Color online) Emission spectra calculated using parameters from Reithmaier et al. [3]. The zero dephasing spectra (red dashed line) are downscaled five times compared to the ${\gamma }_p=20\mathrm{GHz}$ spectra (black line). Parameters: $g_0=38\mathrm{GHz}$, $\kappa =43\mathrm{GHz}$, $\gamma =0.1\mathrm{GHz}$.

Figure 5

Schematic of the mechanic model system. The mass $m_c$ is connected to the wall at $x=0$ through a spring with force constant $k_c$ and to the piston through a spring with force constant $g_c$. The position of the piston is given as $f\left(t\right)$.