Asymptotics of correlation functions of the Heisenberg-Ising chain in the easy-axis regime. (8th January 2016)

• Record Type: Journal Article
• Authors: Dugave, Maxime; Göhmann, Frank; Kozlowski, Karol K; Suzuki, Junji
• Is Part Of: Journal of physics. Volume 49:Number 7(2016)
• Publication Date: 2016-01-08
• Subjects: quantum spin chain -- correlation functions -- exact asymptotic results -- quantum communication; Mathematical physics -- Periodicals; Statistical physics -- Periodicals; Quantum theory -- Periodicals; Matter -- Properties -- Periodicals; 530.105
• DOI: 10.1088/1751-8113/49/7/07LT01
• Languages: English
• ISSNs: 1751-8113

Abstract

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 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 . As a special case we obtain the explicit form of the asymptotics of the auto-correlation function.