Europhysics Letters (EPL)
New Results for q -State Vertex Models and the Pure Biquadratic Spin-1 Hamiltonian
Andreas Klümper
Abstract
New exactly solvable SO(q) -invariant q -state vertex models are introduced. We employ a new method using inversion relations which enables us to determine directly the spectra of the transfer matrices. The results are applied to related quantum spin chains. A special case is the pure biquadratic spin-1 Hamiltonian which turns out to be noncritical. Various quantities are calculated, e.g. , the energy gap and the correlation length.