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arXiv · 1702.04039

Dirac fermion reflector by ballistic graphene sawtooth-shaped npn junctions

Sei Morikawa·Quentin Wilmart·Satoru Masubuchi·Kenji Watanabe·Takashi Taniguchi·Bernard Plaçais·Tomoki Machida
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Abstract

We have realized a Dirac fermion reflector in graphene by controlling the ballistic carrier trajectory in a sawtooth-shaped npn junction. When the carrier density in the inner p-region is much larger than that in the outer n-regions, the first straight np interface works as a collimator and the collimated ballistic carriers can be totally reflected at the second zigzag pn interface. We observed clear resistance enhancement around the np+n regime, which is in good agreement with the numerical simulation. The tunable reflectance of ballistic carriers could be an elementary and important step for realizing ultrahigh-mobility graphene field effect transistors utilizing Dirac fermion optics in the near future.

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Sei Morikawa, Quentin Wilmart, Satoru Masubuchi, Kenji Watanabe, Takashi Taniguchi, Bernard Plaçais, Tomoki Machida. 2017-02-14. Dirac fermion reflector by ballistic graphene sawtooth-shaped npn junctions. https://doi.org/10.1088/1361-6641/aa6102

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