Is there a conflict between causality and diamagnetism?
Quantum Physics
2025-11-06 v3 Materials Science
Other Condensed Matter
Optics
Abstract
There is a long-standing apparent conflict between the existence of diamagnetism and causality as expressed through the Kramers-Kronig relations. In essence, using causality arguments, along with a small number of seemingly well-justified assumptions, one can show that diamagnetism is impossible. However, experiments show diamagnetic responses from magnetic media. We present a resolution to this issue, which also explains the absence of observed dia-electric responses in media. In the process, we expose some of the short-comings in earlier analyses that have kept the paradox alive.
Cite
@article{arxiv.2501.13098,
title = {Is there a conflict between causality and diamagnetism?},
author = {Niclas Westerberg and Stephen M. Barnett},
journal= {arXiv preprint arXiv:2501.13098},
year = {2025}
}
Comments
12 pages + appendices, 2 figures. Published version