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arXiv · 1105.0587

Greenberger-Horne-Zeilinger states and few-body Hamiltonians

Paolo Facchi·Giuseppe Florio·Saverio Pascazio·Francesco V. Pepe
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Abstract

The generation of Greenberger-Horne-Zeilinger (GHZ) states is a crucial problem in quantum information. We derive general conditions for obtaining GHZ states as eigenstates of a Hamiltonian. In general, degeneracy cannot be avoided if the Hamiltonian contains m-body interaction terms with m<=2 and a number of qubits strictly larger than 4. As an application, we explicitly construct a two-body 4-qubit Hamiltonian and a three-body 5-qubit Hamiltonian that exhibit a GHZ as a nondegenerate eigenstate.

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Paolo Facchi, Giuseppe Florio, Saverio Pascazio, Francesco V. Pepe. 2011-05-03. Greenberger-Horne-Zeilinger states and few-body Hamiltonians. https://doi.org/10.1103/physrevlett.107.260502

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