  The spin interaction between an electron and nuclei was investigated
optically in a single self-assembled InAlAs quantum dot (QD). In spin dynamics,
the correlation time of the coupled electron-nuclear spin system and the
electron spin relaxation time play a crucial role. We examined on a positively
charged exciton in a QD to evaluate these key time constants directly via the
temporal evolution measurements of the Overhauser shift and the degree of
circular polarization. In addition, the validity of our used spin dynamics
model was discussed in the context of the experimentally obtained key
parameters.
