Quantum Entanglement and Modulation Enhancement of Free-Electron–Bound-Electron Interaction

The modulation and engineering of the free-electron wave function bring new ingredients to electron-matter interaction. We consider dynamics a passing by two-level system fully quantum mechanically study enhancement interaction from function. In presence resonant function, we show that electron energy loss gain spectrum is greatly enhanced for coherent initial state system. Thus, modulated can as probe atomic coherence. further find distantly separated atoms be entangled through interacting with same free electron. Effects modulation-induced also observed using dilute beam electrons.