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arXiv · 2207.04286

Fundamental asymmetries between spatial and temporal boundaries in electromagnetics

Wending Mai·Jingwei Xu·Douglas H. Werner
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Abstract

Time-varying materials bring an extra degree of design freedom compared to their conventional time-invariant counterparts. However, few discussions have focused on the underlying physical difference between spatial and temporal boundaries. In this letter, we thoroughly investigate those differences from the perspective of conservation laws. By doing so, the building blocks of optics and electromagnetics such as the reflection law, Snell's law, and Fresnel's equations can be analogously derived in a temporal context, but with completely different interpretations. Furthermore, we study the unique features of temporal boundaries, such as their nonconformance to energy conservation and causality.

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Wending Mai, Jingwei Xu, Douglas H. Werner. 2022-07-09. Fundamental asymmetries between spatial and temporal boundaries in electromagnetics. https://doi.org/10.3390/sym15040858

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