Here we analytically study the process of spontaneous generation of photon pairs from the vacuum in a photonic time crystal. We unveil the link between the classical and quantum electrodynamical properties of photonic time crystals, showing a direct relation between reflectivity and pair generation through the squeezing parameter. Congratulations to Jaime for having his first paper published!

Quantum Theory of Photon Pair creation in Photonic Time Crystals (PDF)
Jaime Echave-Sustaeta, Francisco J. García-Vidal, P. A. Huidobro,
ACS Photonics 12, 4, 1873–1880 (2025)
arXiv:2405.05043