Perspectives

Active matter locally dissipates energy to produce systematic motion. This Perspective highlights proliferation as a special type of activity that breaks particle number conservation and thereby gives rise to a unique set of collective phenomena characteristic of life.

Atomic gases, usually confined in flat geometries, are now experimentally realized also in curved settings. This Perspective article analyses their many-body physics in the available geometries of rings and shells and discusses the open research questions.

Superconductivity and cascades of correlated phases have been discovered in Bernal bilayer and rhombohedral trilayer graphene. This Perspective reviews the recent experimental findings and provides an analysis of the theoretical models that aim to explain them.

Modern society relies on many interdependent networks such as electric grids, supply chain networks and ecological networks. This Perspective describes progress and challenges in harnessing insights from statistical physics and control theory to develop better control and management strategies of such complex networks and infrastructure systems.

Physical non-equilibria can drive cycles of replication and selection chemistries that play a role in the prebiotic replication of DNA and RNA. This Perspective offers insights from astrophysics, geoscience and microfluidics on how various environments on early Earth could have hosted such reactions.

Even for flows as simple as those through pipes and channels, the nature of the transition to turbulence has remained elusive. This Perspective discusses how statistical mechanics and specifically directed percolation may provide an answer to this old problem.

For many complex or living systems, it is impossible to individually sample all their units, but subsampling can heavily bias the inference about their collective properties. This Perspective presents the subsampling problem and reviews recent developments to overcome this fundamental limitation.

Scientific understanding is one of the main aims of science. This Perspective discusses how advanced computational systems, and artificial intelligence in particular, can contribute to driving scientific understanding.

In this Perspective on the physics of particle generation in the respiratory tract, fate in the air upon exhalation and the physics of inhalation, the authors conclude that the general understanding of the entire process is rudimentary, and many open questions remain.

Topological quantum materials host protected, high-mobility surface states which can be used for energy conversion and storage. This Perspective discusses recent progress in using topological materials for water splitting, batteries and supercapacitors.

The standard Hamiltonian approach to quantum field theory violates Poincaré invariance, leading to predictions with artificial dynamical effects and potentially obscuring the fundamental description of a physical system. This Perspective explains how such issues are avoided by using light-front Hamiltonian quantization.

Finding the most appropriate machine learning algorithm for the analysis of any given scientific dataset is currently challenging, but new machine learning benchmarks for science are being developed to help.

Chemically active, flexible sheets convert chemical energy into the flow of the surrounding fluid, which, in turn, transforms the sheet’s shape. This Perspective describes how this feedback produces shape-changing 3D objects, coupled oscillators exhibiting spatiotemporal coordination and the rotation of chemically driven gears.

Nanoscopic chiroptics studies the spin-dependent asymmetric light–matter interactions at the nanoscale, where the asymmetry can stem from the intrinsic properties of materials, structures or light. This Perspective establishes an overarching framework for nanoscopic chiroptics across the spatial, moment and integrated spatial–momentum dimensions, and discusses applications enabled by this approach.

Graphene nanoribbons are an emerging class of 1D materials hosting rich quantum-confined and topological states. This Perspective discusses recent breakthroughs in graphene nanoribbon materials and devices, and identifies key challenges towards electronics and quantum information applications.

This Perspective describes how visualizations help to understand several key aspects of big science projects: productivity and impact over different phases, evolution of teams and their management, big data and cyberinfrastructure, and measuring and communicating success.

The study of hypernuclei contributes to the understanding of the fundamental baryonic interactions and the physics of neutron stars. This Perspective discusses different experimental approaches to answer open questions regarding hypernuclei.

The recent measurement of a nonlinear Hall effect has provided a new way to probe the spectral, symmetry and topological properties of quantum materials. This Perspective discusses the open questions around this new effect and potential applications.

Blending occurs when multiple sources of light occupy the same region of the sky. This Perspective discusses the problems arising from blending for astrophysical and cosmological studies, and introduces the two main strategies for solutions.

The Weyl orbit is a type of cyclotron orbit that appears in topological semimetals. This Perspective discusses the Weyl orbit in the context of the 3D quantum Hall effect and provides an outlook on new phenomena that can arise from these states.