Controlled Remote Preparation Via the Brown State with no Restriction

Two controlled remote state preparation protocols via the Brown state as the entangled channel are proposed. One prepares an arbitrary two-qubit state, and the other prepares an arbitrary three-qubit state. It is worth mentioning that Hurwitz matrix equation plays a key role in the construction of measurement basis. Comparing with the previous protocols, the novel schemes have no restriction on the coefficients of the prepared state while keeping the same success probability 50 %. It means that the application of the proposed schemes are more extensive in practice. Moreover, we discuss the special complex coefficient ensembles with unit success probability.