391607.fig.006a
(a)
391607.fig.006b
(b)
Figure 6: (a) 𝑋 + line selective population by intra-dot excitation. FSS is not observed since the two 𝑋 + states with their total spin of ± 1 / 2 are degenerated. (b) Detection polarization-selective PL spectra of the 𝑋 + line measured under the 𝜎 + excitation. Red curve is a result of co-circular ( 𝜎 + ) detection, while the blue curve is a result of cross-circular ( 𝜎 ) detection. The degree of circular polarization defined by ( 𝐼 𝜎 + 𝐼 𝜎 ) / ( 𝐼 𝜎 + + 𝐼 𝜎 ) is as high as 0.85 without external magnetic field.