Polarization-dependent shift in excitonic Zeeman splitting of self-assembled In 0.75 Al 0.25 As ∕ Al 0.3 Ga 0.7 As quantum dots

We report optical spectroscopic results of a single self-assembled ${\mathrm{In}}_{0.75}{\mathrm{Al}}_{0.25}\mathrm{As}∕{\mathrm{Al}}_{0.3}{\mathrm{Ga}}_{0.7}\mathrm{As}$ quantum dot. The polarization-dependent shift of the Zeeman splitting in a single InAlAs quantum dot (QD) has been observed. The induced Overhauser field is estimated to be $\ensuremath{\sim}0.16\phantom{\rule{0.3em}{0ex}}\mathrm{T}$ in this InAlAs QD and the magnitude is shown to be controllable by the degree of circular polarization of excitation light.