Quantum tasks using six qubit cluster states

The usefulness of the recent experimentally realized six photon cluster state by C. Y. Lu et al. (2007 Nature 3 91), is investigated for quantum communication protocols like teleportation, quantum information splitting (QIS), remote state preparation and dense coding. We show that the present state can be used for the teleportation of an arbitrary two qubit state deterministically. Later we devise two distinct protocols for the QIS of an arbitrary two qubit state among two parties and systematically compare their relative merits in terms of classical communication and security. Sixteen orthogonal measurement basis on the cluster state is constructed, which will lock an arbitrary two qubit state among two parties. The usefulness of the state for dense coding is investigated and it is shown that one can send five classical bits by sending only three qubits using this state as a shared entangled resource. We finally show that this state can also be utilised in the remote state preparation of an arbitrary two qubit state.