Three-level systems exhibit quantum interference effects absent in two-level systems, making them important for quantum optics. Here, we study the coherent interaction of a $\mathrm{\Lambda }$-type three-level system with free electrons shaped by optical near fields. By treating the electron train as a quantum drive, we show that the interplay between electron modulation and the three-level system’s transition pathways induces tunable interference patterns. This interaction effectively realizes electron-mediated coherent population trapping. We identify a regime that enables complete population transfer between the two lower states and the preparation of a high-coherence superposition, manifested as dark states. In particular, these driven-dissipative steady states are independent of the initial state. Our Letter proposes shaped free electrons as a platform for steady-state coherent control of three-level systems, enabling atomic-scale state engineering.

Close

PrevNext

View figure in article

• Coherent control
• Electron beams & optics
• Quantum optics
• Relativistic & quantum electrodynamic effects in atoms, molecules,& ions
• Scattering of atoms, molecules, clusters & ions