Asymptotic Behavior of the Emptiness Formation Probability in the Critical Phase of XXZ Spin Chain
V. E. Korepin, C.N. Yang, Sergei L. Lukyanov, Yoshihiro Nishiyama, Masahiro Shiroishi
Abstract
We study the Emptiness Formation Probability (EFP) for the spin 1/2 XXZ spin chain. EFP P (n) detects a formation of ferromagnetic string of the length n in the ground state. It is expected that EFP decays in a Gaussian way for large strings P (n) n . Here, we propose the explicit expressions for the rate of Gaussian decay C as well as for the exponent . In order to con rm the validity of our formulae, we employed an ab initio simulation technique of the density-matrix renormalization group to simulate XXZ spin chain of sucient length. Furthermore, we performed Monte-Carlo integration of the Jimbo-Miwa multiple integral for P (n). Those numerical results for P (n) support our formulae fairly de nitely.