Quantum antireflection temporal coatings: quantum state frequency shifting and inhibited thermal noise amplification

We investigate the quantum optical response of antireflection temporal coatings, i.e., matching temporal layers that suppress the generation of backward waves in temporal boundaries. Our results reveal that quantum antireflection temporal coatings are characterized for inducing a frequency shift of the quantum state, while preserving all photon statistics intact. Thus, they might find application for fast quantum frequency shifting in photonic quantum networks. The quantum theory also provides additional insight on their classical mode of operation, clarifying which quantities are preserved through the temporal boundary. Finally, we show that quantum antireflection temporal coatings allow for fast temporal switching without the amplification of thermal fields.