Physics

Gate controlled valley polarizer in bilayer graphene

H. Chen, P. Zhou, et al.

Discover how sign reversal of Berry curvature in bilayer graphene leads to counter-propagating 1D channels with distinct valley indices. This groundbreaking research, conducted by Hao Chen, Pinjia Zhou, Jiawei Liu, Jiabin Qiao, Barbaros Oezyilmaz, and Jens Martin, achieves impressive conductance differences without requiring an external magnetic field—unlocking new possibilities for future experiments.

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Abstract

Sign reversal of Berry curvature across two oppositely gated regions in bilayer graphene can give rise to counter-propagating 1D channels with opposite valley indices. Previous work achieved good contrast only with an external magnetic field, limiting applications. This paper presents improved performance through optimized device geometry and stacking, showing a two-order-of-magnitude conductance difference between valley-polarized and gapped states, paving the way for zero-magnetic-field experiments.

Publisher

Nature Communications

Published On

Mar 05, 2020

Authors

Hao Chen, Pinjia Zhou, Jiawei Liu, Jiabin Qiao, Barbaros Oezyilmaz, Jens Martin