The current magnetization hypothesis as a microscopic theory of the {\O}rsted magnetic field induction

Abstract

A wire that conducts an electric current will give rise to circular magnetic field (the \O{}rsted 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 has can reproduce a range of experimental observations. A key implication of this equation is that the induction of \O{}rsted magnetic field is only a result of the displacement of charge. A possible microscopic origin of \O{}rsted 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 could resolve the apparent contradiction between the observed induced 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 conductors.