Ultrafast holography enabled by quantum interference of ultrashort electrons

TL;DR

This paper introduces a novel ultrafast holography technique using quantum interference of electrons, achieving attosecond/nanometer resolution in an electron microscope, enabling advanced imaging and quantum measurements.

Contribution

The authors demonstrate a new method for ultrafast electron holography using quantum superposition, surpassing traditional spatial interference approaches, with potential for quantum optics applications.

Findings

Achieved attosecond/nanometer resolution in electron holography.

Implemented quantum interference of electron energy states for imaging.

Enabled optically-controlled quantum measurements with high spatial and temporal precision.

Abstract

Holography relies on the interference between a known reference and a signal of interest to reconstruct both the amplitude and phase of that signal. Commonly performed with photons and electrons, it finds numerous applications in imaging, cryptography and arts. With electrons, the extension of holography to the ultrafast time domain remains a challenge, although it would yield the highest possible combined spatio-temporal resolution. Here, we show that holograms of local electromagnetic fields can be obtained with combined attosecond/nanometer resolution in an ultrafast transmission electron microscope (UEM). Unlike conventional holography, where the signal and the reference are spatially separated and then recombined to interfere, in our method we use electromagnetic fields to split an electron wave function in a quantum coherent superposition of different energy states. In the image plane, spatial modulation of the electron-energy distribution reflects the phase relation between reference and signal fields, which we map via energy-filtered UEM. Beyond imaging applications, this approach allows implementing optically-controlled and spatially-resolved quantum measurements in parallel, providing an efficient and versatile tool for the exploration of electron quantum optics.