Néel Temperature of Quasi-Low-Dimensional Heisenberg Antiferromagnets

This is the authors' abstract. We don't add key points for this paper.

The N\'eel temperature TN of quasi-one- and quasi-two-dimensional antiferromagnetic Heisenberg models on a cubic lattice is calculated by Monte Carlo simulations as a function of interchain (interlayer) to intrachain (intralayer) coupling J^'/J down to J^'/J10^-3. We find that TN obeys a modified random-phase approximationlike relation for small J^'/J with an effective universal renormalized coordination number, independent of the size of the spin. Empirical formulas describing TN for a wide range of J^' and useful for the analysis of experimental measurements are presented.