In our new theory work published in Physical Review Letters, we explore the interaction of slow electrons (up to 200 eV kinetic energy) with a light field. Slow electrons reveal new physics compared to fast electrons, whose interactions with light are well known and used for a wide range of applications. We found that slow electrons cannot exchange energy with the light field indefinitely, but instead are limited in their energy gain and get trapped. We show that this trapping can get extremely strong so that the interaction is effectively reduced to a two-level system, which is widely used in quantum optics, but now realized with electrons. Our research could enable a new type of quantum simulator where the energy states and the energy exchange of the electron-light interactions can be tailored. We are delighted that our paper has been chosen as Editor’s suggestion, which is a big honor! You will find the paper under this link.