Spin stiffness in frustrated antiferromagnets

The classical antiferromagnetic Heisenberg model on the triangular lattice is studed using Monte Carlo techniques. The behavior of the antiferromagnetic structure factor, antiferromagnetic correlation length, and spin stiffness at low temperatures is consistent with recent low-temperature renormalization-group predictions based on a nonlinear sigma model (NLσ) description of the system. Our results support the validity of the NLσ model approach to the study of frustrated systems.