Exact Form-Factor Results for the Longitudinal Structure Factor of the Massless XXZ Model in Zero Field

J. -S. Caux, H. Konno, M. Sorrell +1

We consider the XXZ quantum spin chain in its massless, disordered regime at zero field. We derive an exact expression for the two-spinon form-factor of $S^z=1/2{\sigma }^z$ by taking a li…