  Many quantum state preparation methods rely on a combination of dissipative
quantum state initialization, followed by unitary evolution to a desired target
state. Here we demonstrate the usefulness of quantum measurement as an
additional tool for quantum state preparation. Starting from a pure separable
multipartite state, a control sequence, which includes rotation, spin squeezing
via one-axis twisting, quantum measurement and post-selection, generates a
highly entangled multipartite state, which we refer to as Projected Squeezed
states (or PS states). Through an optimization method, we then identify
parameters required to maximize the overlap fidelity of the PS states with the
maximally entangled Greenberger-Horne-Zeilinger states (or GHZ states). The
method leads to an appreciable decrease in state preparation time of GHZ states
when compared to preparation through unitary evolution with one-axis twisting
only.
