  The concrete schemes to realize three types of basic quantum logical gates
using linear quadripartite cluster states of optical continuous variables are
proposed. The influences of noises and finite squeezing on the computation
precision are analyzed in terms of the fidelity of propagated quantum
information through the continuous variable cluster states. The proposed
schemes provide direct references for the design of experimental systems of
one-way quantum computer based on the cluster entanglement of amplitude and
phase quadratures of light.
