The interlayer exchange coupling in Fe/MgO(001) superlattices is found to increase exponentially with decreasing temperature. Around 150~K, the field induced response changes from discrete switching, governed by field-driven domain propagation, to a collective rotation of the magnetic layers. This transition is accompanied by a change in the magnetic ground state from 180∘ (antiferromagnetic) to 90∘ alignment between adjacent Fe layers. These effects are argued to arise from quantum well states, defined by the total thickness of the samples.
@article{arxiv.2505.05141,
title = {Exponential Dependence of Interlayer Exchange Coupling in Fe/MgO(001) Superlattices on Temperature},
author = {Nanny Strandqvist and Tobias Warnatz and Kristbjörg Anna Thórarinsdóttir and Alexei Vorobiev and Vassilios Kapaklis and Björgvin Hjörvarsson},
journal= {arXiv preprint arXiv:2505.05141},
year = {2025}
}