An Exactly Solvable Constrained XXZ Chain

Abstract

A new family of exactly solvable models is introduced. These models are generalizations of the XXZ chain where the distance among spins up (${\sigma }^z$-basis) cannot be smaller or equal to t (t=0,1,2,...). The case t=0 recovers the standard XXZ chain. The coordinate Bethe ansatz is applied and the phase diagram is calculated. Exploring the finite-size consequences of conformal invariance the critical exponents are evaluated exactly at the critical regions of the phase diagram

13 pages with 3 figures included inm ain tex. To appear in the Proceedings of the Conference: Statistical Physics on the Eve of the Twenty-Fist Century - (World Scientific 1999)