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Focusing of Electron Beam via a Ferromagnetic Gate in Graphene
New Phys.: Sae Mulli 2019; 69: 989~992
Published online October 31, 2019;
© 2019 New Physics: Sae Mulli.

Gukhyung IHM*

Department of Physics, Chungnam National University, Daejeon 34134, Korea
Correspondence to:
Received June 10, 2019; Revised August 26, 2019; Accepted August 27, 2019.
cc This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
In graphene, the linear dispersion and zero-gap band structure admit highly transparent n$-$p junctions due to simple electrostatic gating. The transparent ballistic n$-$p junctions of graphene with electrostatic gates have been known to exhibit negative refractive behavior. In this work, the focusing of an electron beam by using a single n$-$p junction with an additional ferromagnetic gate in graphene is theoretically studied. The additional use of the ferromagnetic gate in the p-type region is found to provide a step-like magnetic barrier in the applied region and leads to an up-and-down movement of the focal point of the beam. Thus, position control of the focal point of the focused beam is now possible either up-and-down through the magnetic potential or right-and-left through the electrostatic potential applied in the gate. Our results pave the way for realizing electron optics based on graphene n$-$p junctions.
PACS numbers: 72.80.Vp, 75.47.$-$m, 78.20.Jq
Keywords: Focusing, Electron beam, Graphene, Ferromagnetic gate

October 2019, 69 (10)
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