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Time-Dependent Entropy Evolution in Microscopic and Macroscopic Electromagnetic Relaxation



James R. Baker-Jarvis


As nanoscale electromagnetic measurements become more common, it is important for the understanding of microstructural electromagnetic interactions to keep pace. The use of time-dependent entropy in the analysis and measurement metrology of electromagnetic interactions with materials is not well-developed. In this paper we study time-dependent polarization entropy and entropy production upon application of electromagnetic fields to materials. An understanding of entropy and its evolution bridges the boundaries between electromagnetism and thermodynamics and is another diagnostic tool for characterizing high-frequency properties of materials. The approach uses a Liouville-based statistical-mechanical theory. I show that the microscopic entropy is reversible and the macroscopic entropy satisfies a H-theorem. I derive new equations for the entropy and entropy production and apply them to functions of the applied, polarization, magnetization, and macroscopic fields. I begin with a fundamental quantum-mechanical analysis of entropy, progress to entropy in electromagnetics, I then apply our theory to relevant applications in electromagnetics, and conclude with a discussion of the Fourier transformed entropy, the spectral entropy, and its relationship to the permittivity, permeability, and impedance. I also extract the spectral entropy from our dielectric measurements.
Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)


Constitutive relations, dielectric relaxation, entropy, entropy, statistical mechanics response


Baker-Jarvis, J. (2005), Time-Dependent Entropy Evolution in Microscopic and Macroscopic Electromagnetic Relaxation, Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) (Accessed March 5, 2024)
Created December 22, 2005, Updated June 2, 2021