“…The overlap formula in this form was first derived for the Néel state (|VBS 1 ) in the Heisenberg model [45][46][47] by exploiting connections [48] to the six-vertex partition function with specific boundary conditions [49]. As for higher-rank spin chains, rigorous derivations JHEP09(2021)004 are seldom available, but many overlap formulas were conjectured [12,26,27,30] or deduced from scattering theory [10,13,36], coordinate Bethe ansatz [50] and TBA [44].…”