Radiative heat and momentum transfer from materials with broken symmetries: opinion

Broken inversion and time reversal symmetries affect the electromagnetic wave modes supported by continuous media, which in turn governs thermal radiation and enables control of radiative heat, linear momentum, and angular momentum transfer. We identify opportunities for exploring thermal radiation in inversion symmetry- and time reversal symmetry-breaking materials and compare and contrast radiative transport phenomena in these systems, especially nonreciprocity. Application of these phenomena can lead to novel methods of thermal management, tunability, and object manipulation at short length scales.