Articles in 2021

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.

Increasing public and private investment, technological breakthroughs, and a growing number of facilities could bring fusion technology to the delivery era by mid-century. Matteo Barbarino argues that global cooperation and effective regulation are vital in accelerating progress.

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.

Sylvia Biscoveanu explains how likelihood reweighting can help estimate the parameters of complex models at a fraction of the computational cost of traditional methods, empowering the analysis of gravitational-wave data.

December 2021 closes our third year of publication. To celebrate, we look at the links between our review-type articles, and think about what articles we might publish next.

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.

Forty years ago saw the introduction of stochastic resonance — the counter-intuitive idea that noise may help a nonlinear system respond to a weak signal.

In 1961, Rolf Landauer noted that erasing one bit of information has a thermodynamics cost. This observation explained Maxwell’s demon paradox and was influential in the early days of quantum computing.