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arXiv · 2209.09669

Ferroelectric valley valves with graphene/MoTe$_2$ van der Waals heterostructures

Adolfo O. Fumega·Jose L. Lado
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Abstract

Ferroelectric van der Waals heterostructures provide a natural platform to design a variety of electrically controllable devices. In this work, we demonstrate that AB bilayer graphene encapsulated in MoTe$_2$ acts as a valley valve that displays a switchable built-in topological gap, leading to ferroelectrically driven topological channels. Using a combination of ab initio calculations and low energy models, we show that the ferroelectric order of MoTe$_2$ allows the control of the gap opening in bilayer graphene and leads to topological channels between different ferroelectric domains. Moreover, we analyze the effect that the moir\'e modulation between MoTe$_2$ and graphene layers has in the topological modes, demonstrating that the edge states are robust against moir\'e modulations of the ferroelectrically-induced electric potential. Our results put forward ferroelectric/graphene heterostructures as versatile platforms to engineer switchable built-in topological channels without requiring an external electric bias.

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Adolfo O. Fumega, Jose L. Lado. 2022-09-20. Ferroelectric valley valves with graphene/MoTe$_2$ van der Waals heterostructures. https://doi.org/10.1039/d2nr05185k

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