Splitting Quantum Information Via Six-qubit Maximally Entangled State And N-tangle Of Superposition Of GHZ States

Quantum entanglement has supplied many interesting applications in the fieldof quantum information in the last few years, such as quantum teleportation,quantum dense coding, quantum secret sharing, quantum cloning and so on.Entanglement of two or more particles is the most intriguing characteristic ofquantum mechanics. In recent years, several physical system have been suggested togenerate quantum entanglement. Secret sharing is the general term for acommunication task in which one participant (the sender) wants to share a messagewith multiple other participants (the recipients) in a way that forces the recipients tocooperate with one another to reconstruct the message. In QIS, a piece of quantuminformation (in the form of a quantum state) is divided and distributed to a number ofreceivers. Quantum information splitting (QIS) or quantum state sharing is thegeneralization of classical secret sharing schemes to the quantum scenario. The firstQIS protocols were proposed by Hillery et al.. Since then many other protocols havebeen proposed, and the topic still attracts much attention today.Quantum entanglement is a key element for applications of quantumcommunications and quantum information. In particular, the entanglement can beused as a quantum resource to carry out a number of computational and informationprocessing tasks, which include teleportation of an unknown quantum state.Quantum teleportation is a prime example of a quantum information processing task,which an unknown state can be perfectly transported from one place to another byusing previously shared entanglement and classical communication between thesender and the receiver. Analysis of such quantum phenomena may provide us abetter understanding of the structure of the quantum mechanics framework.Therefore, it is important to find out the ways of classifying and quantifying theentanglement properties of quantum states. The idea that locally invariant quantitiescan be used to characterize entanglement is central to this work. Invariants underlocal unitary (LU) and more general transformations, such as, stochastic localoperations and classical communication(SLOCC), have been extensively studied inthis context.This paper describes the two aspects. At first, Propose a schemes of splittingtwo-qubit states by using six-particle maximally entangled state as the quantumchannel. Alice first performs two Bell-basis measurement and announces hermeasurement outcome and assigns Charlie (Bob) to reconstruct the original unknownstate. If the controllers Bob (Charlie) agree to help Charlie (Bob) obtain the originalstate, they should perform single-particle measurements on their respective qubits.After the sender performs Bell-basis measurements on her particles, and thecooperators operate single-particle measurements on their particles, the state receiver can reconstruct the original state of the sender by applying the appropriate unitaryoperation.Second, use the n-tangle, as a measure of entanglement to investigate thesuperposition of Greenberger-Horne-Zeilinger states for even n qubits. The papershow that orthogonal basis with the GHZ state can be divided into two group viaSLOCC–invariant. In the same group, an expression for any two superposed state isprovided, when the superposition coefficient is real, the n-tangle of superposed stateis invariable. Otherwise, In the different group, which can get a different expressionif the superposed state come from different group.