Theory of Coexisting Transverse Spin Freezing and Long-Ranged Antiferromagnetic Order in Lightly Doped La_{2-x}Sr_x CuO_4

TL;DR

This paper explains the observed spin-freezing transition in lightly doped La_{2-x}Sr_x CuO_4 by proposing topological excitations in a 2D Heisenberg antiferromagnet that match experimental data.

Contribution

It introduces a novel topological excitation model to explain spin-freezing and antiferromagnetic order in lightly doped cuprates, aligning theory with experimental observations.

Findings

Topological excitations account for spin-freezing temperatures.

Qualitative and quantitative agreement with experimental data.

New insight into magnetic behavior in doped cuprates.

Abstract

We provide an explanation of the spin-freezing transition recently observed by Chou et al. (Phys. Rev. Lett. 71, 2323 (1993)) in La_{2-x}Sr_x CuO_4 for x <= 0.02. We propose that topological excitations of the 2D Heisenberg quantum antiferromagnet having non-coplanar transverse components have a pair-interaction energy that qualitatively and quantitatively agrees with the observed values of spin-freezing temperature as a function of doping.