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Monte Carlo Study of Correlations in Quantum Spin Chains at Non-Zero Temperature

Y. J. Kim·M. Greven·U. -J. Wiese·R. J. Birgeneau
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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 $S$=2 chains which have a gap $Δ$, the correlation length and the uniform susceptibility in the temperature range $Δ< T < J$ are well predicted by a semi-classical theory due to Damle and Sachdev.

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Y. J. Kim, M. Greven, U. -J. Wiese, R. J. Birgeneau. 1998-08-18. Monte Carlo Study of Correlations in Quantum Spin Chains at Non-Zero Temperature. https://doi.org/10.1007/s100510050382

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