Free Electrons to Bound Electrons and Photons Quantum Coherent Coupling

Quantum coherence, a cornerstone of modern physics, encompasses phenomena like quantum entanglement and Rabi oscillations, which lack classical analogs. FreeQCC seeks to expand the frontiers of quantum mechanics by leveraging advances in free electron beam nanophysics and quantum nano-optics. Key questions include whether a free electron can be entangled with an atom or photon, and if a solid qubit's quantum coherence can be imprinted onto a free electron beam. By exploiting the quantum properties of free electron beams and their interactions with matter and radiation, FreeQCC aims to reveal atomic-scale dynamics and quantum coherence effects previously inaccessible. The project will develop cutting-edge experiments using advanced electron and optical microscopy technologies, enabling precise control and measurement of free electrons and photons' quantum states. This includes measuring at the nanoscale optical polarization of nanophotonic devices via free electrons linear and orbital angular momentum transfer and photon polarization, and characterizing nanometric artificial atoms with ultra-high spatial and spectral resolution. These efforts will demonstrate entanglement between free electrons and photons mediated by plasmons, and the measurement of Rabi oscillations in individual artificial atoms with free electron beams. FreeQCC addresses the challenge of balancing temporal, energetic, and spatial resolutions while maintaining the sensitivity and cryogenic conditions needed to preserve quantum coherence. Ultimately, FreeQCC aims to provide new insights into quantum mechanics and open unprecedented opportunities for manipulating and measuring quantum coherence at the nanoscale, potentially pioneering a new field in free electron physics and introducing a groundbreaking tool for quantum information technologies.