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arXiv · 2410.05636

Gapped Dirac materials and quantum valley currents in dual-gated hBN/bilayer-graphene heterostructures

Takuya Iwasaki·Yoshifumi Morita·Kenji Watanabe·Takashi Taniguchi
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Abstract

In gapped Dirac materials, the topological current associated with each valley can flow in opposite directions creating long-range charge-neutral valley currents. We report valley currents in hBN/bilayer-graphene heterostructures with an energy gap, which is tunable by a perpendicular electric (displacement) field in a dual-gated structure. We observed significant nonlocal resistance, consistent with the scaling theory of the valley Hall effect. In the low-temperature limit, the nonlocal resistance approaches a saturated value near the "quantum limit," indicating the emergence of quantum valley currents.

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Takuya Iwasaki, Yoshifumi Morita, Kenji Watanabe, Takashi Taniguchi. 2024-10-08. Gapped Dirac materials and quantum valley currents in dual-gated hBN/bilayer-graphene heterostructures. https://arxiv.org/abs/2410.05636

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