arXiv:1105.4447 · Physical Review Letters
Computation of Static Heisenberg-Chain Correlators: Control over Length and Temperature Dependence
Jun Sato, Britta Aufgebauer, Herman E. Boos, Frank Göhmann, Andreas Klümper, Minoru Takahashi, Christian Trippe
Abstract
We communicate results on correlation functions for the spin-1/2 Heisenberg chain in two particularly important cases: (a) for the infinite chain at arbitrary finite temperature T, and (b) for finite chains of arbitrary length L in the ground state. In both cases we present explicit formulas expressing the short-range correlators in a range of up to seven lattice sites in terms of a single function ω encoding the dependence of the correlators on T (L). These formulas allow us to obtain accurate numerical values for the correlators and derived quantities like the entanglement entropy. By calculating the low T (large L) asymptotics of ω we show that the asymptotics of the static correlation functions at any finite distance are T(2) (1/L(2)) terms. We obtain exact and explicit formulas for the coefficients for up to eight sites.