Entanglement in SU„2...-invariant quantum spin systems
نویسنده
چکیده
We analyze the entanglement of SU~2!-invariant density matrices of two spins SW 1 , SW 2 using the PeresHorodecki criterion. Such density matrices arise from thermal equilibrium states of isotropic-spin systems. The partial transpose of such a state has the same multiplet structure and degeneracies as the original matrix with the eigenvalue of largest multiplicity being non-negative. The case S15S , S251/2 can be solved completely and is discussed in detail with respect to isotropic Heisenberg spin models. Moreover, in this case the PeresHorodecki criterion turns out to be a sufficient condition for nonseparability. We also characterize SU~2!invariant states of two spins of length 1.
منابع مشابه
Entanglement in SU(2)-invariant quantum systems: The positive partial transpose criterion and others
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تاریخ انتشار 2003