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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 4 Issue 3 (1998) pp 291-297
Monte-Carlo study of correlations in quantum spin chains at non-zero temperature
Y.J. Kim (1)(2) (a), M. Greven (1) (b), U.-J. Wiese (1), R.J. Birgeneau (1)
(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
Received: 23 December 1997 / Revised and Accepted: 11 March 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, $T/J \approx 0.01$. 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 $\Delta$, the correlation length and the uniform susceptibility in the temperature range $\Delta < T < J$ are well predicted by the semi-classical theory of Damle and Sachdev.
PACS. 75.10.Jm Quantized spin models - 75.40.Cx Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.) - 75.40.Mg Numerical simulation studies
(a) email: ykim@yoko.mit.edu
(b) Present address: Department of Applied Physics and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, CA 94305, USA.
Article in PDF-Format (627 KB)
Online publication: August 17, 1998
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