Easy-to-configure zero-dimensional valley-chiral modes in a graphene point junction.

Davydov, Konstantin; Zhang, Xi; Ren, Wei; Coles, Matthew; Kline, Logan; Zucker, Bryan; Watanabe, Kenji; Taniguchi, Takashi et al. · Sci Adv · 2024

basic_science · Level V

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Abstract

The valley degree of freedom in two-dimensional (2D) materials can be manipulated for low-dissipation quantum electronics called valleytronics. At the boundary between two regions of bilayer graphene with different atomic or electrostatic configuration, valley-polarized current has been realized. However, the demanding fabrication and operation requirements limit device reproducibility and scalability toward more advanced valleytronics circuits. We demonstrate a device architecture of a point junction where a valley-chiral 0D PN junction is easily configured, switchable, and capable of carrying valley current with an estimated polarization of ~80%. This work provides a building block in manipulating valley quantum numbers and scalable valleytronics.