  We have investigated the dynamics of the electron-nuclei coupled system in
quantum dots. The bunching of results of the electron spin measurements and the
revival in the conditional probabilities are salient features of the nuclear
spin memory. The underlying mechanism is the squeezing of the nuclear spin
state and the correlations between the successive electron spin measurements.
Further we make a proposal for the preparation and detection of superposition
states of nuclear spins merely relying on electron spin measurements. For
unpolarized, completely random nuclear spin state one can still trace the
quantum interference effects. We discuss the realization of these schemes for
electron spins on both single and double QDs.
