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Entanglement of degenerate ground state for spin 1 and 1/2 pair

You-Quan Li·Guo-Qiang Zhu·Xue-An Zhao
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Abstract

We study the entanglement feature of the ground state of a system composed of spin 1 and 1/2 parts. The concurrence vector is shown to be consistent with the measurement of von Neumann entropy for such system. In the light of the ground state degeneracy, we suggest a average concurrence to measure the entanglement of Hilbert subspace. The entanglement property of both a general superposition as well as the mixture of the degenerate ground states are discussed by means of average concurrence and the negativity respectively.

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You-Quan Li, Guo-Qiang Zhu, Xue-An Zhao. 2004-09-01. Entanglement of degenerate ground state for spin 1 and 1/2 pair. https://arxiv.org/abs/quant-ph/0408155

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