Thermodynamics of integrable $$ \mathcal{N} $$ = 2 theories, squared

A bstract In arXiv:2306.17553 a new supersymmetric integrable QFT was constructed from the relativistic limit of the worldsheet theory of AdS 3 × S 3 ×T 4 superstrings with mixed Ramond-Ramond and Neveu-Schwarz-Neveu-Schwarz flux. The model is closely reminiscent of one previously considered by Fendley and Intriligator, though it enjoys twice as many supersymmetries. In this paper we study its finite-volume and finite-temperature properties. We formulate the string hypothesis for the Bethe-Yang equations, write down the thermodynamic Bethe ansatz equations, and simplify them in the form of a Y-system. We obtain three decoupled sectors associated with massive, massless-chiral and massless-antichiral particles, for which we compute the UV central charge. We illustrate the similarities and differences between this model and the one of Fendley and Intriligator.