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arXiv · 2310.07992

Spin and Valley Polarized Multiple Fermi Surfaces of {\alpha}-RuCl$_3$/Bilayer Graphene Heterostructure

Soyun Kim·Jeonghoon Hong·Kenji Watanabe·Takashi Taniguchi·Joseph Falson·Jeongwoo Kim·Youngwook Kim
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Abstract

We report the transport properties of ${\alpha}$-RuCl$_3$/bilayer graphene heterostructures, where carrier doping is induced by a work function difference, resulting in distinct electron and hole populations in ${\alpha}$-RuCl3 and bilayer graphene, respectively. Through a comprehensive analysis of multi-channel transport signatures, including Hall measurements and quantum oscillation, we unveil significant band modifications within the system. In particular, we observe the emergence of spin and valley polarized multiple hole-type Fermi pockets, originating from the spin-selective band hybridization between ${\alpha}$-RuCl$_3$ and bilayer graphene, breaking the spin degree of freedom. Unlike ${\alpha}$-RuCl$_3$ /monolayer graphene system, the presence of different hybridization strengths between ${\alpha}$-RuCl$_3$ and the top and bottom graphene layers leads to an asymmetric behavior of the two layers, confirmed by effective mass experiments, resulting in the manifestation of valley-polarized Fermi pockets. These compelling findings establish ${\alpha}$-RuCl$_3$ proximitized to bilayer graphene as an outstanding platform for engineering its unique low-energy band structure.

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Soyun Kim, Jeonghoon Hong, Kenji Watanabe, Takashi Taniguchi, Joseph Falson, Jeongwoo Kim, Youngwook Kim. 2023-10-12. Spin and Valley Polarized Multiple Fermi Surfaces of {\alpha}-RuCl$_3$/Bilayer Graphene Heterostructure. https://doi.org/10.1063/5.0170810

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