On form-factor expansions for the XXZ chain in the massive regime. (28th May 2015)

• Record Type: Journal Article
• Authors: Dugave, Maxime; Göhmann, Frank; Kozlowski, Karol K; Suzuki, Junji
• Is Part Of: Journal of statistical mechanics. (2015:May)
• Publication Date: 2015-05-28
• Subjects: 1 -- 3; 1/040 -- 1/050 -- 1/100 -- 3/090; Statistical mechanics -- Periodicals; Mechanics -- Statistical methods -- Periodicals; 530.1305
• DOI: 10.1088/1742-5468/2015/05/P05037
• Languages: English
• ISSNs: 1742-5468

Abstract

Abstract: We study the large-volume- L limit of form factors of the longitudinal spin operators for the XXZ spin-1/2 chain in the massive regime. We find that the individual form factors decay as L − n, n being an even integer counting the number of physical excitations—the holes—that constitute the excited state. Our expression allows us to derive the form-factor expansion of two-point spin–spin correlation functions in the thermodynamic limit L → +∞. The staggered magnetisation appears naturally as the first term in this expansion. We show that all other contributions to the two-point correlation function are exponentially small in the large-distance regime.