Chiral coordinate Bethe ansatz for phantom eigenstates in the open XXZ spin-$\frac{1}{2}$ chain

Xin Zhang, Andreas Kluemper, Vladislav Popkov

We construct the coordinate Bethe ansatz for all eigenstates of the open spin-$\frac{1}{2}$ XXZ chain that fulfill the phantom roots criterion (PRC). Under the PRC, the Hilbert space s…