COQUVAR · Controlling Quantum Vacuum Radiation: Transient Amplification and Squeezing in the Dynamical Casimir Effect

Quantum vacuum fluctuations can give rise to real particles, with the dynamical Casimir effect (DCE) being a paradigmatic example. When the boundary conditions or the material properties of a cavity vary rapidly in time, vacuum fluctuations are converted into photons. The photons are emitted as entangled pairs and form a two-mode squeezed state, making the emitted radiation a valuable resource for quantum communication and quantum metrology.The proposed project aims to analyse and control the photon generation in the DCE. First, a scattering framework will be developed and the concept of pseudounitarity will be incorporated into the framework of DCE, to describe the energy exchange between positive and negative frequency modes. The quantum Wigner–Smith operator will also be constructed to enable wavefront shaping techniques. Second, the project will explore parameter regions where the photon emission occurs transiently over finite time intervals, rather than through the usual resonant mechanism of the DCE that leads to exponential growth. The wavefront shaping techniques will then be employed to control the radiation intensity so that it reaches a desired value at a selected time. Finally, strategies will be developed to manipulate the degree of squeezing of the emitted light, addressing both clean and disordered environments.By combining Floquet theory, pseudospectrum analysis, and wavefront shaping techniques, the project will establish new ways of tailoring the properties of the quantum vacuum radiation, with outcomes of direct relevance for future quantum technologies.