  Grover search is a well-known quantum algorithm that outperforms any
classical search algorithm. It is known that quantum correlations such as
entanglement are necessary for the power of quantum computation. But
entanglement is not the only kind of quantum correlations. Other quantum
correlations such as quantum discord are also useful to capture some aspects of
the nonclassical correlation. We investigate several kinds of correlations
including both quantum and classical in the whole process of Grover search
algorithm. These correlations are the concurrence, entanglement of formation,
quantum discord, classical correlation and mutual information. The behaviors of
quantum discord, classical correlation and mutual information are almost the
same while the concurrence is different. When the search is over, all kinds of
correlations are zero, we argue that this is necessary for the final step in
the search.
