Square-Lattice Heisenberg Antiferromagnet at Very Large Correlation Lengths

B. B. Beard, R. J. Birgeneau, M. Greven, U.-J. Wiese
1998 Physical Review Letters  
The correlation length of the square-lattice spin-1/2 Heisenberg antiferromagnet is studied in the low-temperature (asymptotic-scaling) regime. Our novel approach combines a very efficient loop cluster algorithm -- operating directly in the Euclidean time continuum -- with finite-size scaling. This enables us to probe correlation lengths up to ξ≈ 350,000 lattice spacings -- more than three orders of magnitude larger than any previous study. We resolve a conundrum concerning the applicability of
more » ... asymptotic-scaling formulae to experimentally- and numerically-determined correlation lengths, and arrive at a very precise determination of the low-energy observables. Our results have direct implications for the zero-temperature behavior of spin-1/2 ladders.
doi:10.1103/physrevlett.80.1742 fatcat:fyno3g64sfcfdkywi63wa6hpzu