QUANTUM INTEGRALS OF MOTION FOR THE HEISENBERG SPIN CHAIN
Marek Grabowski, Pierre Mathieu · Modern Physics Letters A · 1994
An explicit expression for all the quantum integrals of motion for the isotropic Heisenberg s=1/2 spin chain is presented. The conserved quantities are expressed in terms of a sum over simple polynomials in spin variables. This construction is direct and independent of the transfer matrix formalism. Continuum limits of these integrals in both ferromagnetic and antiferromagnetic sectors are briefly discussed.