The $$ {D}_3^{(2)} $$ spin chain and its finite-size spectrum

Abstract

Abstract Using the analytic Bethe ansatz, we initiate a study of the scaling limit of the quasi-periodic $$ {D}_3^{(2)} $$ D 3 2 spin chain. Supported by a detailed symmetry analysis, we determine the effective scaling dimensions of a large class of states in the parameter regime γ ∈ (0,$$ \frac{\pi }{4} $$ π 4 ). Besides two compact degrees of freedom, we identify two independent continuous components in the finite-size spectrum. The influence of large twist angles on the latter reveals also the presence of discrete states. This allows for a conjecture on the central charge of the conformal field theory describing the scaling limit of the lattice model.