Asymptotics of correlation functions of the Heisenberg-Ising chain in the easy-axis regime

作者：Dugave Maxime; Goehmann Frank; Kozlowski Karol K; Suzuki Junji

来源：Journal of Physics A-Mathematical and Theoretical, 2016, 49(7): 07LT01.

DOI：10.1088/1751-8113/49/7/07LT01

• quantum spin chain
• correlation functions
• exact asymptotic results
• quantum communication

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.

• 出版日期2016-2-19