Topological states characterized by Chern numbers are usually considered to be the global properties of a material. Now a spatial patchwork of different Chern insulator states is imaged in twisted bilayer graphene.

Experiments at the Joint European Torus tokamak show improved thermal ion confinement in the presence of highly energetic ions and Alfvénic instabilities in the plasma.

Both inter- and intraband transitions contribute to high-harmonic generation in solids, but their exact roles are not fully understood. Experiments with quantum dots show that enhanced intraband transitions lead to increased carrier injection and thus enhanced harmonic generation.

A method to engineer higher-order interactions between photons provides a route to create non-classical and entangled states across multiple modes.

Magnetic skyrmions—a type of localized spin texture—have been theoretically predicted to annihilate with counterparts known as antiskyrmions. By means of electron microscopy, such annihilation has now been observed in a cubic chiral magnet.

Combinatorial optimization is one of the areas for which quantum computing promises to overcome classical devices. An experiment with arrays of Rydberg atoms now shows how to solve combinatorial graph problems with auxiliary atomic wires.

Glass, now celebrated with a dedicated International Year, continues to fascinate.

The shift of the definition of the kilogram in 2019 away from an artefact to one relying on the Planck constant inspires technological innovation, as Naoki Kuramoto elucidates.

Against the backdrop of various philosophical accounts, this Comment argues for the need of a human rights approach to scientific progress, which requires us to rethink how we view scientific knowledge.

As conventions in scholarly publishing evolve, it is appropriate to reassess the options that we provide to our authors. In this spirit, Nature Physics will soon stop accepting submissions in our Letter format.