arXiv:cond-mat/0703319 · Journal of Physics A Mathematical and Theoretical
Dynamical correlation functions of theXXZmodel at finite temperature
Kazumitsu Sakai
Abstract
Combining a lattice path integral formulation for thermodynamics with the solution of the quantum inverse scattering problem for local spin operators, we derive a multiple integral representation for the time-dependent longitudinal correlation function of the spin-1/2 Heisenberg XXZ chain at finite temperature and in an external magnetic field. Our formula reproduces the previous results in the following three limits: the static, the zero-temperature and the XY limits.