"Novel Electron Imaging Methods Based on Light-Mediated Coherent Electron Wave Function Shaping"

Giovanni Maria Vanacore

Laboratory of Ultrafast Microscopy for Nanoscale Dynamics (LUMiNaD), Department of Materials Science, University of Milano-Bicocca, Via Cozzi 55, 20126 Milano.

Abstract:

The interaction between light and electrons can be exploited for generating radiation, or for controlling electron beams for dynamical investigation of materials, enabling new applications in quantum technologies and microscopy. In this contribution, I will describe an innovative method for coherent and versatile longitudinal/transverse manipulation of a free-electron wave function. Using appropriately shaped light fields in space and time, I will demonstrate how to modulate the energy, linear and orbital angular momenta, as well as spatial and temporal distributions of the electron wave function. The experiments have been performed in an ultrafast-TEM, where a pulsed electron beam was made to interact with a shaped optical field generated via a spatial light modulator, and the energy-momentum exchange resulting from such interaction was directly mapped in the electron multidimensional phase space. We will demonstrate how our approach for arbitrary longitudinal/transverse electron modulation at the sub-fs timescale is fundamental for the first time implementation of new imaging techniques, such as Ramsey-like holography and Single Pixel Imaging, as well as for enhanced TEM performance, such as spherical aberration correction. Our results would pave the way for achieving unprecedented insights into non-equilibrium phenomena in advanced quantum materials, playing a decisive role in the rational design and engineering of future photonics and electronics application.