Integrable Quantum Mappings and Quantization Aspects of Integrable   Discrete-time Systems
  We study a quantum Yang-Baxter structure associated with non-ultralocal lattice models. We discuss the canonical structure of a class of integrable quantum mappings, i.e. canonical transformations preserving the basic commutation relations. As a particular class of solutions we present two examples of quantum mappings associated with the lattice analogues of the KdV and MKdV equations, together with their exact quantum invariants. plain LaTeX, equations.sty appended 
F.W. Nijhoff and H.W. Capel (Clarkson University)