Path-separated electron interferometry in a scanning transmission electron microscope. (26th April 2018)

• Record Type: Journal Article
• Authors: Yasin, Fehmi S; Harvey, Tyler R; Chess, Jordan J; Pierce, Jordan S; McMorran, Benjamin J
• Is Part Of: Journal of physics. Volume 51:Number 20(2018)
• Publication Date: 2018-04-26
• Subjects: electron interferometry -- electron microscopy -- scanning transmission electron microscopy -- electron holography; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/aabc47
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: We report a path-separated electron interferometer within a scanning transmission electron microscope. In this setup, we use a nanofabricated grating as an amplitude-division beamsplitter to prepare multiple spatially separated, coherent electron probe beams. We achieve path separations of 30 nm. We pass the +1 diffraction order probe through amorphous carbon while passing the 0th and −1 orders through vacuum. The probes are then made to interfere via imaging optics, and we observe an interference pattern at the CCD detector with up to 39.7% fringe visibility. We show preliminary experimental results in which the interference pattern was recorded during a 1D scan of the diffracted probes across a test phase object. These results qualitatively agree with a modeled interference predicted by an independent measurement of the specimen thickness. This experimental design can potentially be applied to phase contrast imaging and fundamental physics experiments, such as an exploration of electron wave packet coherence length.