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Solving the open XXZ spin chain with nondiagonal boundary terms at roots of unity

Rafael I. Nepomechie
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Abstract

We consider the open XXZ quantum spin chain with nondiagonal boundary terms. For bulk anisotropy value η= i π/(p+1), p= 1, 2, ..., we propose an exact (p+1)-order functional relation for the transfer matrix, which implies Bethe-Ansatz-like equations for the corresponding eigenvalues. The key observation is that the fused spin-(p+1)/2 transfer matrix can be expressed in terms of a lower-spin transfer matrix, resulting in the truncation of the fusion hierarchy.

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Rafael I. Nepomechie. 2002-03-05. Solving the open XXZ spin chain with nondiagonal boundary terms at roots of unity. https://doi.org/10.1016/s0550-3213(01)00585-5

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