Quantum 2D Heisenberg antiferromagnet: bridging the gap between field-theoretical and semiclassical approaches

Abstract

The field-theoretical result for the low-$T$ behaviour of the correlation length of the quantum Heisenberg antiferromagnet on the square lattice was recently improved by Hasenfratz [Eur. Phys. J. B {\bf 13}, 11 (2000)], who corrected for cutoff effects. We show that starting from his expression, and exploiting our knowledge of the classical thermodynamics of the model, it is possible to take into account non-linear effects which are responsible for the main features of the correlation length at intermediate temperature. Moreover, we find that cutoff effects lead to the appearance of an effective exchange integral depending on the very same renormalization coefficients derived in the framework of the semiclassical {\em pure-quantum self-consistent harmonic approximation}: The gap between quantum field-theoretical and semiclassical results is here eventually bridged.

4 pages, 1 figure

References in corpus (7)

• Asymptotic scaling of the square lattice quantum Heisenberg antiferromagnet
• The Square-Lattice Heisenberg Antiferromagnet at Very Large Correlation Lengths
• Spin Dependence of Correlations in Two-Dimensional Quantum Heisenberg Antiferromagnets
• Lattice Perturbation Theory for $O(N)$-Symmetric $\sigma$-Models with General Nearest-Neighbour Action I. Conventional Perturbation Theory
• Temperature dependent correlation length for the S=1/2 Quantum Heisenberg Antiferromagnet on the square lattice
• The correlation length of the Heisenberg antiferromagnet with arbitrary spin S
• Reconciling the correlation length for high-spin Heisenberg antiferromagnets

Cited by in corpus (1)

• Quantum Heisenberg antiferromagnets: a survey of the activity in Firenze