Ultrafast Kapitza-Dirac effect
Abstract
Similar to the optical diffraction of light passing through a material grating, the Kapitza-Dirac effect occurs when an electron is diffracted by a standing light wave. In its original description the effect is time-independent. In the present work, we extend the Kapitza-Dirac concept to the time domain. By tracking the spatiotemporal evolution of a pulsed electron wave packet diffracted by a femtosecond (10 15 second) standing wave pulse in a pump-probe scheme, we observe so far unseen time-dependent diffraction patterns. The fringe spacing in the observed pattern differs from that generated by the conventional Kapitza-Dirac effect, moreover it decreases as the pump-probe delay time increases. By exploiting this time-resolved diffraction scheme, we gather access to the time evolution of the previously inaccessible phase properties of a free electron.
Cite
@article{arxiv.2404.00304,
title = {Ultrafast Kapitza-Dirac effect},
author = {Kang Lin and Sebastian Eckart and Hao Liang and Alexander Hartung and Sina Jacob and Qinying Ji and Lothar Ph. H. Schmidt and Markus S. Schöffler and Till Jahnke and Maksim Kunitski and Reinhard Dörner},
journal= {arXiv preprint arXiv:2404.00304},
year = {2024}
}