Front Cover: Quantum Sensing with Extreme Light (Adv. Quantum Technol. 6/2022)

Quantum sensing provides access to photon properties in spectral ranges classically hard to address. As demonstrated by Mirco Kutas, Björn Erik Haase, Felix Riexinger, and colleagues in article number 2100164, this allows to combine the best of both spectral ranges, i.e. the significance of spectral information in the terahertz range with the high sensitivity of detectors in the visible spectral range. The cover artistically visualizes this entanglement between terahertz photons (red) and visible photons (green).