Download file (2.35 MB)
Download as zip (1.9 MB)

Collection

Citation

Description:

The relativistic charge carriers in monolayer graphene can be manipulated in manners akin to conventional optics(electron-optics): angle-dependent Klein tunneling collimates an electron beam (analogous to a laser), while a Veselago refraction process focuses it (analogous to an optical lens). Both processes have been previously investigated, but the collimation and focusing efficiency have been reported to be relatively low even in state-of-the-art ballistic PN-junction devices. These limitations prevent the realization of more advanced quantum devices based on electron-optical interference, and the underlying physics remains elusive. In this work, we develop a novel device architecture of a graphene microcavity defined by carefully-engineered local strain and electrostatics. We realize a controlled electron-optic interference process at zero magnetic field via a consequence of consecutive Veselago refractions in the microcavity and demonstrate direct experimental evidence via low-temperature electrical transport measurement. First, we show that the observed interference peaks (first-, second-, and third-order) agree quantitatively with the Veselago physics in a microcavity. Second, we demonstrate decoherence of the interference by an external magnetic field, as the cyclotron radius becomes comparable to the interference length scale. For its application in electron-optics, we utilize Veselago interference to further localize uncollimated electrons and characterize its contribution in further improving collimation efficiency. Our work sheds new light on relativistic single-particle physics and provides important technical improvement toward next-generation quantum devices based on the coherent manipulation of electron momentum and trajectory.

Rights:

• Creative Commons BY Attribution 4.0 International
  

Keyword: elativistic charge carriers, graphene microcavity, Veselago interference

Date published: 2022-11-07

Publisher: Springer Science and Business Media LLC

Journal:

• Nature Communications (ISSN: 20411723) vol. 13 issue. 1 6711

Funding:

• United States Department of Defense | United States Army | U.S. Army Research, Development and Engineering Command | Army Research Office ARO MURI Grant No. W911NF14-0247

Manuscript type: Publisher's version (Version of record)

MDR DOI:

First published URL: https://doi.org/10.1038/s41467-022-34347-w

Related item:

Other identifier(s):

Contact agent:

Updated at: 2025-02-27 16:30:33 +0900

Published on MDR: 2025-02-27 16:30:33 +0900