Deterministic Joint Remote Preparation of a Four-qubit Cluster-type   State via GHZ states
  A scheme for the deterministic joint remote preparation of a four- qubit cluster-type state using only two Greenberger-Horne-Zeilinger (GHZ) states as quantum channels is presented. In this scheme, the first sender per- forms a two-qubit projective measurement according to the real coefficient of the desired state. Then, the other sender utilizes the measurement result and the complex coefficient to perform another projective measurement. To obtain the desired state, the receiver applies appropriate unitary operations to his/her own two qubits and two CNOT operations to the two ancillary ones. Most interestingly, our scheme can achieve unit success probability, i.e., Psuc=1. Furthermore, comparison reveals that the efficiency is higher than that of most other analogous schemes. 
Hai-bin Wang, Xiao-Yan Zhou, Xing-xing An, Meng-Meng Cui, De-sheng Fu
quant-ph