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arXiv · 1509.04867

Q-operators for the open Heisenberg spin chain

Rouven Frassek·Istvan M. Szecsenyi
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Abstract

We construct Q-operators for the open spin-1/2 XXX Heisenberg spin chain with diagonal boundary matrices. The Q-operators are defined as traces over an infinite-dimensional auxiliary space involving novel types of reflection operators derived from the boundary Yang-Baxter equation. We argue that the Q-operators defined in this way are polynomials in the spectral parameter and show that they commute with transfer matrix. Finally, we prove that the Q-operators satisfy Baxter's TQ-equation and derive the explicit form of their eigenvalues in terms of the Bethe roots.

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Rouven Frassek, Istvan M. Szecsenyi. 2015-10-22. Q-operators for the open Heisenberg spin chain. https://doi.org/10.1016/j.nuclphysb.2015.10.010

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