Bilayer Graphene Slides into Action
For the past 15 years, physicists have been fascinated by twisted bilayer graphene, a structure formed by stacking two sheets of graphene and rotating one relative to the other. Depending on the twist angle, this material can exhibit magnetism, superconductivity, and various other electronic phenomena (see Trend: Bilayer Graphene’s Wicked, Twisted Road). Now Zhe Wang at Xi’an Jiaotong University in China and his colleagues have demonstrated an alternative way to adjust the electronics of bilayer graphene [1]. Their technique involves sliding one sheet over the other without rotation and could be applied to a wide range of 2D material systems.
Scientists have previously predicted that such interlayer sliding in bilayer graphene would greatly affect the material’s electronic and topological properties. However, that prediction had not been confirmed experimentally because the sliding approaches proposed so far either required many-layer material systems or led to unstable atomic configurations. In the new method, which lacks those limitations, bilayer graphene is placed over a microscopic metal ridge. This deformation induces a controlled sliding between the material’s two layers, in the same way that bending a stack of playing cards causes each card to slide with respect to its neighbors.
Wang and his colleagues harnessed their technique to realize tailored atomic arrangements that were previously unattainable. In one such arrangement, electrons could travel through eight parallel 1D channels, as revealed by electronic transport measurements. Each channel was topologically protected, meaning that these electrons traveled without being scattered by material defects or impurities. Such topological channels could be useful for electronics applications.
–Ryan Wilkinson
Ryan Wilkinson is a Corresponding Editor for Physics Magazine based in Durham, UK.
References
- J. Pan et al., “Topological valley transport in bilayer graphene induced by interlayer sliding,” Phys. Rev. Lett. 135, 126603 (2025).