A recursive two-phase general protocol on deterministic remote preparation of a class of multi-qubit states

In this work, we present a general scheme to realize a remote preparation of a class of multi-qubit states (RSP) with real parameters using EPR-type pairs in a deterministic way. Our scheme operates essentially by breaking down the RSP protocol into two phases. In the first phase, the remote preparer can pre-adjust the initial channel to a target channel with proper ancilla-assisted unitary transformation operations. In the second phase, a projective measurement on a group of suitably chosen orthogonal bases is performed by the preparer. The results show that our two-phase RSP protocols are entirely feasible to deterministically prepare a class of multi-qubit states with real parameters for the remote receiver via pre-distributed Bell-type channels. In addition, since the pre-distributed channel could be used in a recursive manner, the efficiency of precious qubit resource can be greatly enhanced.