Operator content of the multicritical magnetic hard-square model

Abstract

The transfer matrix spectra of the magnetic hard squares along the multicritical line are analysed using the data for the strip width N up to 12. The operator content of the model is exactly the same as that of the Ashkin-Teller model. When N is odd, the spectrum is accounted for by the continuum theory in which the antiperiodic boundary condition is imposed to one of the Ising variables of the Ashkin-Teller model.