Reviews & Analysis

Photonics is one of the key platforms for emerging quantum technologies, but its full potential can only be harnessed by exploiting miniaturization via on-chip integration. This Roadmap charts new directions and discusses the challenges associated with the hybrid integration of a variety of materials, devices and components.

In 2021, the most precise measurement of the muon’s anomalous magnetic moment and a new high-precision lattice quantum chromodynamics calculation have in turn kindled, then dimmed, hopes for seeing signs of new physics. State-of-the-art calculations, made possible by a series of recent advances, will be key to understanding these conflicting results.

Metamaterials enable precise tailoring of light–matter interactions. This Review discusses recent developments in the use of metamaterials for imaging.

Topological insulators are unique materials giving rise to unconventional quantum phenomena. This Technical Review discusses how various physics effects can only be observed in devices carefully fabricated to address them, including topological superconductivity, quantum anomalous Hall states, spintronic functionalities and topological mesoscopic physics.

Peoples’ movements are linked with the spread of epidemics — but not always in simple ways. In the past two years, new datasets and analyses have shed fresh light on how to relate mobility and contagion.

A key challenge in fabricating devices out of 2D materials is in making good electrical contact. This Expert Recommendation discusses the physics of electrical contacts and provides tips on improving contact quality.

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.

Microwave impedance microscopy, a scanning probe technique that measures local conductivity and permittivity with minimal sample preparation, has become a mature tool with fundamental and practical applications. This Technical Review describes its working principles, applications and future opportunities.

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.

Light–matter interaction in 2D and topological materials provides a fascinating control knob for inducing emergent, non-equilibrium properties and achieving new functionalities in the ultrafast timescale. This Review discusses recent experimental progress on the light-induced phenomena and provides perspectives on the opportunities of proposed light-induced phenomena, as well as open experimental challenges.

Optical superoscillations are rapid spatial variations of the intensity and phase of light. This Review describes technologies for generating superoscillatory hotspots and discuss advances in imaging and metrology with superoscillatory light that, in combination with artificial intelligence, offer deeply subwavelength optical resolution.

Current and future big science projects in India are providing opportunities for young researchers and building technological capabilities, while contributing to new scientific discoveries. Seven scientists involved in these large-scale projects reflect on the impact their project has on the Indian research landscape.

The ability to image nanometre-scale magnetization and current density is key to deciphering the physics of correlated states hosted in 2D layered materials. This Technical Review analyses the magnetic imaging techniques most amenable to these systems, compares their capabilities and limitations, and discusses their potential impact.

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.

There isn’t one single ‘early career experience’ in physics, and different subfields involve very different opportunities and challenges. Seven early career physicists who work on a range of research topics in different subfields discuss their views on the lessons we can learn from their professional lives.

Massive black holes dwell in many galaxies, and various physical processes have been invoked to explain their presence. This Review discusses their formation channels, how they have grown over time from smaller seeds and how we can constrain their origins.

Radiotherapy with accelerated heavy ions is a potential breakthrough in cancer therapy. This Review discusses the challenges in physics and radiobiology to make this therapy affordable and to fully exploit the clinical benefits.

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.

Quantum Hall systems represent an example of topological quantum matter, where quasiparticles with fractional statistics (anyons) may emerge. This Technical Review presents a survey of recent developments in quantum Hall interferometry.