We demonstrate a 2-grating free electron Mach-Zehnder interferometer constructed in a transmission electron microscope. A symmetric binary phase grating and condenser lens system forms two spatially separated, focused probes at the sample which can be scanned while maintaining alignment. The two paths interfere at a second grating, creating in constructive or destructive interference in output beams. This interferometer has many notable features: positionable probe beams, large path separations relative to beam width, continuously tunable relative phase between paths, and real-time phase information. Here we use the electron interferometer to measure the relative phase shifts imparted to the electron probes by electrostatic potentials as well as a demonstration of quantitative nanoscale phase imaging of a polystyrene latex nanoparticle.
@article{arxiv.2104.09992,
title = {A Scanning 2-Grating Free Electron Mach-Zehnder Interferometer},
author = {Cameron W. Johnson and Amy E. Turner and Benjamin J. McMorran},
journal= {arXiv preprint arXiv:2104.09992},
year = {2021}
}