Quantum symmetry and XXZ model

I discuss the symmetry approach to the XXZ quantum spin chain, an exactly solvable model in quantum statistical mechanics in one-dimension. The model has the quantum affine $sl(2)$ symmetry, and the correlation function satisfies a system of linear $q$-difference equations called the $q$-deformed Knizhnik–Zamolodchikov equation.
The talk is for non-specialsts, and covers some basic facts about solvable lattice models and the quantum affine $sl(2)$ algebra and its representation theory.