Figure 1

The schematic diagram of experimental setup leading to EIT and slow light in an ensemble of charged QD’s. The train of short pulses of ${\sigma }^{+}$-polarized light with frequency ${\omega }_{t0}$ and repetition period $T_R$ generates the electron spin coherence and moves all spin precession frequencies to a single precession mode ${\omega }_e$ [29]. EIT and slow light in this system are tested by the two ${\sigma }^{-}$-polarized light fields with photon frequencies ${\omega }_{+}$ and ${\omega }_{-}$ and pulse amplitudes (Rabi frequencies) ${\Omega }_{+}$ and ${\Omega }_{-}$, respectively. The Voigt states $|\pm \rangle =(|\uparrow \rangle \pm |\downarrow \rangle )/\sqrt{2}$ are created from $|\uparrow \rangle$ and $|\downarrow \rangle$ states by a transverse magnetic field.Reuse & Permissions

Figure 2

Pulse-matching propagation through a QD sample with the optical density $D=20$. Calculations were conducted for the electron $g$ factor $g=-0.45$ in a magnetic field $B=5$ T for both homogeneous and inhomogeneous samples. The inhomogeneity was introduced via the $g$-factor dispersion width ${\Delta }_g=0.005$, which results in a dispersion of $\Delta {\varepsilon }_e=1.4\hspace{0.5em}\mu$eV. (a) The time dependence of output pulses $|{\Omega }_{+}(t)|{}^2$ (filled circles) and $|{\Omega }_{-}(t)|{}^2$ (empty circles) after light propagation through a homogenous QD sample for the input pulse $\left|{\Omega }_{+}\right|{}^2$ (filled squares) with peak intensity in arbitrary units $\left|{\Omega }_{+}\right|{}^2=1$ and $\left|{\Omega }_{-}\right|{}^2=0$, (empty squares). Inset: The dependence of the peak intensity of the output pulses $\left|{\Omega }_{+}\right|{}^2$ and $\left|{\Omega }_{-}\right|{}^2$ on the optical density $D$ for the homogenous (solid lines) and inhomogeneous (dashed lines) samples. (b) Pulse-matching effect calculated for $|{\Omega }_{+}(t)|{}^2$ (filled square) and $|{\Omega }_{-}(t)|{}^2$ (empty square) input pulses with different temporal widths after propagating through a homogenous QD sample. The effect of inhomogeneity on the output pulses is shown for both the (c) amplitude and (d) temporal width matching cases.Reuse & Permissions

Figure 3

Slow-light propagation through a QD ensemble, which has been pumped into a single spin precession mode. The dashed curves show delayed pulses $\Delta \Omega (t)={\Omega }_{+}(t)-{\Omega }_{-}(t)$, after the sample propagation calculated for several values of the carrier field amplitude ${\Omega }_0=0.8,0.6,0.45$ and $0.4$ GHz. The solid curve shows the reference pulse. The relaxation rate of the trion is $\Gamma =2.5$ GHz, the optical density of the sample is $D=40$, and the total length is 4 cm. Inset shows the dependence of the delay time on ${\Omega }_0$.Reuse & Permissions