Abstract : We analyse the long-time large-distance asymptotics of the longitudinal correlation functions of the Heisenberg-Ising chain in the easy-axis regime. We show that in this regime the leading asymptotics of the dynamical two-point functions is entirely determined by the two-spinon contribution to their form factor expansion. Its explicit form is obtained from a saddle-point analysis of the corresponding double integral. It describes the propagation of a wave front with velocity nu(c1) which is found to be the maximal possible group velocity. Like in wave propagation in dispersive media the wave front is preceded by a precursor running ahead with velocity nu(c2). As a special case we obtain the explicit form of the asymptotics of the auto-correlation function.
https://hal-univ-bourgogne.archives-ouvertes.fr/hal-01413200
Contributeur : Imb - Université de Bourgogne <>
Soumis le : vendredi 9 décembre 2016 - 14:46:50
Dernière modification le : mardi 13 décembre 2016 - 09:31:49
