Moiré materials

Thanks to improved control of device fabrication and an expanding characterization toolbox, moiré materials stay in the spotlight as we discover more about the unique phenomena they realize.

Three years after the observation of superconductivity in twisted bilayer graphene, the study of the rich variety of phenomena that arise in moiré materials is keeping researchers fruitfully busy.

More than 40 years after the discovery of the quantum Hall effect, the investigation of new variants of this phenomenon and of the exotic physics they represent is still a lively research topic. In this Viewpoint, five scientists involved in the very recent discovery of a new type of Hall effect — the fractional quantum anomalous Hall effect — discuss their results and their implications.

Moiré systems formed by 2D atomic layers have widely tunable electrical and optical properties and host exotic, strongly correlated and topological phenomena, including superconductivity, correlated insulator states and orbital magnetism. In this Viewpoint, researchers studying different aspects of moiré materials discuss the most exciting directions in this rapidly expanding field.

Moiré materials are an emerging class of strongly correlated quantum materials designed by the rotational or lattice misalignment of 2D crystals. This Review discusses how local probe techniques are uniquely positioned to elucidate the microscopic mechanisms underlying the electronic phases in moiré materials.

Moiré materials are a versatile and tunable platform that offers a wide variety of lattice constants, energy scales and symmetries, leading to a rich interplay of electron correlations and topology. This Review summarizes recent breakthroughs in topological and Berry physics in moiré materials.

Interlayer hybridization in van der Waals stacks is key to understanding their physical properties. This Perspective article discusses the various parameters influencing interlayer hybridization and how they can be controlled, providing a comprehensive guide for designing materials with desired properties.

Flat-band materials such as kagome and moiré lattices and strongly correlated electron systems including heavy-fermion compounds exhibit strikingly similar phenomena of topology and strong correlations. This Perspective article discusses Kondo physics as the underlying theme and a route to a unified understanding.

A paper in the Journal of Applied Physics reports a way to apply strain to two-dimensional devices while measuring simultaneously their electrical and optical properties.

An article in Advanced Materials shows that the moiré superlattice in a ferromagnetic heterostructure comprising a twisted WS₂/WS₂ bilayer enhances the spin–orbit torque efficiency and increases its gate tunability.

An article in Nature Communications reports the identification of two non-volatile spin textures in twisted double-bilayer CrI₃, which can be switched by a magnetic field and read out via electrical measurements.