Low Temperature Static and Dynamic Behaviour of the Easy-Axis Heisenberg Antiferromagnet on the Kagome Lattice

The antiferromagnetic Heisenberg model with easy-axis exchange anisotropy on the Kagome lattice is studied by means of Monte Carlo simulations. From equilibrium properties, we find that the values of the critical exponents associated with the magnetization at the critical temperature $T_c$ vary with the magnitude of the anisotropy. On the other hand, the spin-spin autocorrelation functions have a stretched exponential behavior with a power law divergence of the relaxation time at a glass-like temperature $T_g \sim T_c$. From non-equilibrium dynamics at a fixed temperature below $T_g$, aging effects are found which obey the same scaling laws as in spin glasses and polymers.