Deconfined quantum criticality and generalized exclusion statistics in a non-Hermitian BCS model

We present a pairing Hamiltonian of the Bardeen–Cooper–Schrieffer form which exhibits two quantum critical lines of deconfined excitations. This conclusion is drawn using the exact Bethe ansatz equations of the model which admit a class of analytic solutions. The deconfined excitations obey generalized exclusion statistics. A notable property of the Hamiltonian is that it is non-Hermitian. Although it does not have a real spectrum for all choices of coupling parameters, we provide a rigorous argument to establish that real spectra occur on the critical lines. The critical lines are found to be invariant under a renormalization group map. (fast track communication)