Effective Sublattice Magnetization and Neel Temperature in Quantum Antiferromagnets

TL;DR

This paper derives an analytic expression for the finite temperature sublattice magnetization in 2D quantum antiferromagnets, accurately matching experimental Ne9el temperatures without adjustable parameters.

Contribution

It provides a parameter-free analytic formula for sublattice magnetization in 2D quantum antiferromagnets that aligns with experimental data.

Findings

Reproduces the qualitative phase diagram behavior.

Matches experimental Ne9el temperatures for specific compounds.

Explains deviations by including frustration and 3D effects.

Abstract

We present an analytic expression for the finite temperature effective sublattice magnetization which would be detected by inelastic neutron scattering experiments performed on a two-dimensional square-lattice quantum Heisenberg antiferromagnets with short range N\'eel order. Our expression, which has no adjustable parameters, is able to reproduce both the qualitative behaviour of the phase diagram $M(T)xT$ and the experimental values of the N\'eel temperature $T_{N}$ for either doped YBa$_{2}$Cu$_{3}$O$_{6.15}$ and stoichiometric La$_{2}$CuO$_{4}$ compounds. Finally, we remark that by incorporating frustration and 3D effects as perturbations is sufficient to explain the deviation of the experimental data from our theoretical curves.