REACTION-DIFFUSION PROCESSES DESCRIBED BY 3-STATE QUANTUM CHAINS AND INTEGRABILITY

The master equation of one-dimensional three-species reaction-diffusio n processes is mapped onto an imaginary-time Schrodinger equation. In many cases the Hamiltonian obtained is that of an integrable quantum c hain with known properties. Within this approach we search for three-s tate integrable quantum chains with known spectra and which are relate d to diffusive-reactive systems. Two integrable models are found to ap pear naturally in this context: the U-q ($$$) over cap SU(2)-invariant model with external fields and the three-state UqSU(P/M)-invariant Pe rk-Schultz models with external fields. A non-local similarity transfo rmation which brings the Hamiltonian governing the chemical processes to the known standard forms is described, leading in the case of perio dic boundary conditions to a generalization of the Dzialoshinsky-Moriy a interaction for N-state Hamiltonians (N > 2).