|
The Abraham-Minkowski controversy is theoretical debate originating at the beginning of the 20th century regarding the electrodynamics of moving media. The controversy has become synonymous with a debate over photon momentum in materials, and has implications in optical micromanipulation, which impacts scientific discovery and technology development in chemistry, physics, biology, material engineering, photonics, and medicine. An important, recent advance in the field of electrodynamics identifies a kinetic momentum as the momentum of the fields responsible for center of mass translations and a canonical momentum related to the coupled field and material system. We review the identification of the two subsystems, and show that neither the Abraham nor the Minkowski formulations are physically valid representations of electrodynamics. The Abraham tensor, like the Einstein-Laub tensor, does not represent a valid stress-energy-momentum (SEM) tensor because it is not frame invariance, which is a tenant of relativity. The Minkowski tensor does satisfy relativistic principles, but it violates the principle of causality. In this correspondence, we present the field-kinetic subsystem of macroscopic electrodynamics, which represents the mass-free contributions to the global SEM tensor. We demonstrate that the relation to microscopic electrodynamics by comparing the field-kinetic macroscopic force density with the microscopic force density via a limiting procedure with increasingly small dipoles representation of matter. We also derive the material response contribution to the SEM tensor in causal media demonstrating the canonical momentum of electrodynamics. Through analytical examples, we show how practical optical manipulation experiments are modeled using both the field-kinetic and canonical SEM tensors in electrodynamics.
|
