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Superconducting transmon qubits are an appealing platform for the implementation of quantum error correction 4– 13. This provides us with a very intuitive approach to codes for the quantum erasure channel, purely based on the entanglement required to protect information against losses by use of the parallel teleportation protocol.Quantum error correction stabilizes logical states by operating on arrays of physical qubits in superpositions of their computational basis states 1– 3. In addition, the implementation of QSS schemes from AME states can be conveniently described within the graph state formalism.įinally, we use the insight gained from entanglement in QSS schemes to derive necessary and sufficient conditions for quantum erasure channel and quantum error correction codes that satisfy the quantum Singleton bound, as these codes are closely related to ramp QSS schemes. We show that for all currently known AME states, absolutely maximally entangled graph states can be found, and we were even able to use graph states to find a new AME state for seven three-dimensional systems (qutrits). They allow for efficient bipartite entanglement verification, which makes them a promising candidate for the description of AME states. An equivalence between threshold QSS schemes and AME states shared between an even number of parties is established, and further protocols are designed, such as constructing ramp QSS schemes and open-destination teleportation protocols with AME states as a resource.Īs a framework to work with AME states, graph states are explored. We further prove the existence of AME states for any number of parties, if the dimension of the involved quantum systems is chosen appropriately. With them as a resource, we develop new parallel teleportation protocols, which can then be used to implement quantum secret sharing (QSS) schemes. We then focus on absolutely maximally entangled (AME) states, which are highly entangled multipartite states that have the property that they are maximally entangled for any bipartition. We mostly focus on three qubit states in the GHZ class, and derive upper and lower bounds for the successful transformation probability between two states. This thesis is devoted to getting a better understanding of multipartite entanglement, and its role in various quantum information protocols.įirst, we investigate transformations between multipartite entangled states that only use local operations and classical communication (LOCC). However, especially when it comes to multipartite entanglement, there still remain a lot of mysteries. It is thus important to have a good understanding of entanglement and the role it plays in these protocols. Most applications in quantum information processing make either explicit or implicit use of entanglement.