Guest Editorial Special Cluster on Magnetless Nonreciprocity in Electromagnetics

The papers in this special section examine magnetless nonreciprocity in electromagnetics. Non/reciprocity is a fundamental concept in all branches of physics—classical mechanics, thermodynamics and statistical mechanics, condensed matter physics, electromagnetism and electronics, optics, relativity, quantum mechanics, particle and nuclear physics, and cosmology. It is even ubiquitous in human life experience (e.g. non/reciprocal access, assistance, agreement, treaty, knowledge, or feeling), and it underpins innumerable common devices and technological applications.