Eur. Phys. J. B 4, 291-297 (1998)
https://doi.org/10.1007/s100510050382

Monte-Carlo study of correlations in quantum spin chains at non-zero temperature

¹ Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
² Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA

Corresponding author: ^a ykim@yoko.mit.edu

Received: 23 December 1997
Accepted: 11 March 1998
Published online: 15 August 1998

Abstract

Antiferromagnetic Heisenberg spin chains with various spin values (S=1/2,1,3/2,2,5/2) are studied numerically with the quantum Monte-Carlo method. Effective spin S chains are realized by ferromagnetically coupling n=2S antiferromagnetic spin chains with S=1/2. The temperature dependence of the uniform susceptibility, the staggered susceptibility, and the static structure factor peak intensity are computed down to very low temperatures, . The correlation length at each temperature is deduced from numerical measurements of the instantaneous spin-spin correlation function. At high temperatures, very good agreement with exact results for the classical spin chain is obtained independent of the value of S. For the S=2 chain which has a gap Δ, the correlation length and the uniform susceptibility in the temperature range are well predicted by the semi-classical theory of Damle and Sachdev.