Universal terms in the overlap of the ground state of the spin-1/2 XXZ chain with the N\'eel state

摘要: We analyze universal terms that appear in the large system size scaling of overlap between Neel state and ground spin-1/2 XXZ chain antiferromagnetic regime. In a critical theory, order one term asymptotics such an may be expressed $g$-factors, known context boundary conformal field theory. particular, for model its gapless phase, this provides access to Luttinger parameter. gapped on other hand, simply reflects symmetry broken nature phase. study analytically compute exactly, we use recently derived finite-size determinant formula perform asymptotic expansion. Our analysis confirms predictions theory enables us determine exponent leading correction.