Radiation Forces and the Abraham-Minkowski Problem

TL;DR

This paper reviews recent experiments in radiation pressure and discusses their implications for the Abraham-Minkowski controversy over electromagnetic momentum in matter, emphasizing the interpretative ambiguities and the need for a combined electromagnetic and mechanical analysis.

Contribution

It critically examines experimental claims related to the Abraham-Minkowski problem and highlights the limitations of current experiments in resolving the momentum debate.

Findings

Most experiments cannot distinguish between Abraham and Minkowski tensors.

Inherent ambiguity exists in applying conservation principles to radiation in dielectrics.

Connections between electrodynamics and the Casimir effect suggest limits on quantum field theory parameters.

Abstract

Recent years have witnessed a number of beautiful experiments in radiation optics. Our purpose with this mini-review is to highlight some developments of radiation pressure physics in general, and thereafter to focus on the importance of the mentioned experiments in regard to the classic Abraham-Minkowski problem. That means, what is the "correct" expression for electromagnetic momentum density in continuous matter. In our opinion one sees relatively often that authors over-interpret the importance of their experimental findings with respect to the momentum problem. Most of these experiments are actually unable to discriminate between these energy-momentum tensors at all, since they can be easily described in terms of force expressions that are common for Abraham and Minkowski. Moreover, we emphasize the inherent ambiguity in applying formal conservation principles to the radiation field in a dielectric, the reason being that the electromagnetic field in matter is only a subsystem which has to be supplemented by the mechanical subsystem to be closed. Finally, we make some suggestions regarding the connection between macroscopic electrodynamics and the Casimir effect, suggesting that there is a limit for the magnitudes of cutoff parameters in QFT related to surface tension in ordinary hydromechanics.