Scientific Reports (May 2017)

A nanofabricated, monolithic, path-separated electron interferometer

  • Akshay Agarwal,
  • Chung-Soo Kim,
  • Richard Hobbs,
  • Dirk van Dyck,
  • Karl K. Berggren

DOI
https://doi.org/10.1038/s41598-017-01466-0
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 10

Abstract

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Abstract Progress in nanofabrication technology has enabled the development of numerous electron optic elements for enhancing image contrast and manipulating electron wave functions. Here, we describe a modular, self-aligned, amplitude-division electron interferometer in a conventional transmission electron microscope. The interferometer consists of two 45-nm-thick silicon layers separated by 20 μm. This interferometer is fabricated from a single-crystal silicon cantilever on a transmission electron microscope grid by gallium focused-ion-beam milling. Using this interferometer, we obtain interference fringes in a Mach-Zehnder geometry in an unmodified 200 kV transmission electron microscope. The fringes have a period of 0.32 nm, which corresponds to the [1̄1̄1] lattice planes of silicon, and a maximum contrast of 15%. We use convergent-beam electron diffraction to quantify grating alignment and coherence. This design can potentially be scaled to millimeter-scale, and used in electron holography. It could also be applied to perform fundamental physics experiments, such as interaction-free measurement with electrons.