Thermal emission from time-modulated bodies (Invited Paper)

Thermal emission is one of the most fundamental and ubiquitous radiative process, and it is the cornerstone of multiple technologies including heat and energy management, imaging, camouflage, and gas sensing. In our talk, we will discuss how the temporal modulation of the material properties of a macroscopic body introduces a new regime for thermal emission engineering [Vazquez-Lozano & Liberal, Nature Communications, (2023)],[Vazquez-Lozano & Liberal, Optics & Photonics News (2023)]. First, temporal modulation breaks continuous time-translation symmetry, removing the restrictions imposed by energy conservation, and facilitating Superplanckian emission. Similarly, breaking time-reversal symmetry lifts the restrictions imposed by reciprocity, and facilitates emission unconstrained by Kirchhoffs law. Moreover, temporal modulation facilitates the observation of ultra-fast nonequilibrium effects. Finally, temporal modulation mixes semiclassical thermal emission and quantum vacuum amplification effects, thus opening a new regime where the quantum nature of incandescence must be taken into account [Libera,Vazquez-Lozano, Ganfornina-Andrades, arXiv:2401.09897 (2024)]