Eur. Phys. J. Plus (2022) 137: 378
https://doi.org/10.1140/epjp/s13360-022-02597-8

Regular Article

The current magnetization hypothesis as a microscopic theory of the Ørsted magnetic field induction

¹ Institute for Frontier Materials, Deakin University, 3216, Geelong, VIC, Australia
² ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, 3001, Melbourne, VIC, Australia

Received: 17 September 2021
Accepted: 13 March 2022
Published online: 22 March 2022

Abstract

A wire that conducts an electric current will give rise to a circular magnetic field (the Ørsted magnetic field), which can be calculated using the Maxwell–Ampere equation. For wires with diameters in the macroscopic scale, the Maxwell–Ampere equation is an established physical law that can reproduce a range of experimental observations. A key implication of this equation is that the induction of Ørsted magnetic field is a result of the displacement of charge. A possible microscopic origin of Ørsted magnetic induction was suggested in [J. Mag. Mag. Mat. 504, 166660 (2020)] (will be called the current magnetization hypothesis (CMH) thereupon). The present work establishes computationally, using simplified wire models, that the CMH reproduces the results of the Maxwell–Ampere equation for wires with a square cross section. I demonstrate that CMH can resolve the apparent contradiction between the observed magnetic field and that predicted by the Maxwell–Ampere equation in nanowires, as was reported in [Phys. Rev. B 99, 014436 (2019)]. The CMH shows that a possible reason for such contradiction is the presence of non-conductive surface layers in electric conductors.