Quantum Teleportation And Quantum Information Splitting Based On A Genuinely Entangled Flve-qubit State

Quantum informatics is a newly-sprung cross discipline，which combined withquantum mechanics and information science. Quantum communication is animportant branch of quantum informatics, mainly including quantum teleportation,quantum dense coding, quantum key distribution etc.Quantum teleportation is thetangible proof of quantum nonlocality and plays an important role in the areas ofquantum mechanics. This thesis expounds a scheme for quantum teleportation usingfive-qubit cluster states and another scheme for quantum information spilitting basedon genuinely entangled five-qubit state as quantum channel.Scheme1:We propose a scheme of quantum teleportation of an arbitrarytwo-qubit state by using a five-qubit cluster state as the quantum channel. In ourscheme, the sender needs to perform five-qubit joint von-Neumann measurement onher qubits, the receiver can reconstruct the arbitrary two-qubit by performing someappropriately unitary transformations on his qubits after he knows the measuredresults of the sender. The probability of success of the program is100%.Scheme2:The application of the genuinely entangled five-qubit state isinvestigated for quantum information splitting of an arbitrary two-qubit state. In thisscheme, a genuinely entangled five-qubit state is shared by Alice (a sender), Charlie (acontroller) and Bob (a receiver), and Alice only needs to perform two Bell-statemeasurements and Charlie performs a single-qubit measurement, Bob can reconstructthe arbitrary two-qubit state by performing some appropriately unitarytransformations on his qubits after he knows the measured results of both Alice andCharlie. This quantum information splitting scheme is deterministic, i.e. theprobability of success is100%. In comparison with the quantum information splittingscheme using the same quantum channel [Phys. Rev. A77(2008)032321], thisscheme need not to make four-qubit joint measurement, which makes this schemesimpler than the latter. The presented protocol is showed to be secure against certain eavesdropping attacks.