Entanglement Transfer in a Composite Electron-Ion-Photon System

We study how entanglement in photoionization is transferred from an electron-ion pair to an electron-photon pair by fluorescence. Time-resolved von Neumann entropies are used to establish how information is shared between the particles. Multipartite entanglement, between electron, ion and photon, is found on intermediate timescales. Finally, it is shown how a phase-locked two-pulse sequence allows for the application of time symmetry, mediated by strong coupling, to reveal the entanglement transfer process by measuring the photon number and electron kinetic energy in coincidence.