Published February 21, 2022 | Version v1
Preprint Open

Complete Excitation of Discrete Quantum Systems by Single Free Electrons

  • 1. ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology

Description

We reveal a wealth of nonlinear and recoil effects in the interaction between individual low-energy electrons and samples comprising a discrete number of states. Adopting a quantum theoretical description of combined free-electron and two-level systems, we find a maximum achievable excitation probability of 100%, which requires specific conditions relating to the coupling strength and the transition symmetry, as we illustrate through calculations for dipolar and quadrupolar modes. Strong recoil effects are observed when the kinetic energy of the probe lies close to the transition threshold, although the associated probability remains independent of the electron wave function even when fully accounting for nonlinear interactions with arbitrarily complex multilevel samples. Our work reveals the potential of free electrons to control localized excitations and delineates the boundaries of such control.

Notes

This work has been supported in part by the Spanish MICINN (PID2020-112625GB-I00 and Severo Ochoa CEX2019-000910-S), the Catalan CERCA Program, and Fundaciós Cellex and Mir-Puig.

Files

Complete Excitation of Discrete Quantum Systems by Single Free Electrons.pdf

Additional details

Funding

eNANO – FREE ELECTRONS AS ULTRAFAST NANOSCALE PROBES 789104
European Commission
SMART-electron – ULTRAFAST ALL-OPTICAL SPATIO-TEMPORAL ELECTRON MODULATORS: OPENING NEW FRONTIERS IN ELECTRON MICROSCOPY 964591
European Commission
EBEAM – Electron beams enhancing analytical microscopy 101017720
European Commission