Reconciling field-theoretical and semiclassical approaches to quantum 2D antiferromagnets

Abstract

We show that, starting from the field-theoretical expression for the correlation length ξ of the 2D quantum Heisenberg antiferromagnet corrected for cut-off effects and our knowledge of the classical thermodynamics of the model, the observed temperature dependence of ξ can be reproduced. We find also that the cut-off effects contains the same pure-quantum renormalizations of the pure-quantum self-consistent harmonic approximation semiclassical framework: the gap between quantum field theoretical and semiclassical results is thus bridged.