Talk presented by Bernard Beard

Parallel Session: Spin Models II

Thursday July 1st, 17.40 - 18.00, Room B

Reconciliation of Correlation Length for High-Spin Heisenberg Antiferromagnets

Abstract: We discuss recent progress in the understanding of the temperature and spin dependence of the staggered spin correlation length for the 2-d square lattice Heisenberg antiferromagnet. P. Hasenfratz's recent calculation of cutoff effects in the chiral perturbation theory (CPT) description is shown to have good agreement with low-temperature quantum Monte Carlo (QMC) results for S=1/2, 1, and 5/2. In addition, the pure-quantum self-consistent harmonic approximation (PQSCHA) is shown to agree well with QMC at intermediate and high temperatures for S=5/2. The evidence suggests that CPT-plus-cutoff and PQSCHA jointly describe the numerical results throughout the range of temperature for higher spins.

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