A Quantum Klystron -- Controlling Quantum Systems with Modulated Electron Beams

Dennis Rätzel, Daniel Hartley, Osip Schwartz, Philipp Haslinger

Published 2020-04-21Version 1

Coherent control of quantum transitions generally relies on interactions of the quantum system with electromagnetic waves. We show that the electromagnetic near-field of a current-modulated free-space electron beam can be employed for coherent manipulation of quantum systems. Using Rabi oscillations between hyperfine levels of potassium atoms and magnetic sublevels in nitrogen vacancy centers as examples, we demonstrate that such manipulation can be performed with only classical control over the electron beam itself, and is readily realizable with current technology. Potential challenges like shot noise and decoherence through back action on the electrons are found to be insignificant for our implementation. These results provide a pathway towards electron-mediated delivery of spatially and spectrally tailored electromagnetic fields for quantum control on the nano-scale.