Robotic production line gives 2D materials a twist to produce multilayer structures

A new technique for scalable production of twisted van der Waals heterostructures has been unveiled by US researchers and used to produce twisted stacks with far more layers than previously possible. The applications are as yet unclear, but it could allow engineers to make use of the many fascinating phenomena discovered in twisted multilayer heterostructures such as superconductivity.

Following theoretical predictions by Allan MacDonald of the University of Texas at Austin and colleagues, Pablo Jarillo-Herrero at the Massachusetts Institute of Technology and colleagues showed in 2018 that in bilayer graphene, if the sheets were twisted relative to each other by just 1.1˚, the material could become either a superconductor or a correlated insulator. Subsequently, Jarillo-Herrero’s group and others have discovered exotic behaviour in graphene comprising three, four and five layers, as well as in twisted multilayers of materials like transition metal dichalcogenides and heterostructures.