Reviews & Analysis

The study of higher-dimensional quantum states has seen numerous conceptual and technological developments. This review discusses various techniques for the generation and processing of qudits, which are stored in the momentum, path, time-/frequency-bins, or the orbital angular momentum of photons.

Chemical vapour deposition (CVD) enables the synthesis of high-purity, pinhole-free and conformal polymer thin films. This Review discusses the recent breakthroughs in mechanistically based CVD polymerization processes and designing CVD polymers for a diverse array of applications.

Quantum technologies require an extremely precise functioning of their components which is ensured by sophisticated tools for device characterization. This Technical Review surveys and assesses the currently available tools according to their overall complexity, information gain, and underlying assumptions.

Methods for measuring stress in living cells, tissues and organs are advancing steadily and are increasingly being used for biomedical applications. In this Review, we discuss the concept of tissue stress and the techniques available to measure it in 2D and 3D cell and tissue cultures and in vivo.

Ion traps enable the precise control and manipulation of the quantum state of a trapped ion. This Technical Review discusses the way in which ion-trap microchips can be fabricated and integrated with advanced on-chip features for implementing practical quantum technologies.

In the midst of the COVID-19 pandemic, science is crucial to inform public policy. At the same time, mistrust of scientists and misinformation about scientific facts are rampant. Six scientists, actively involved in outreach, reflect on how to build a better understanding and trust of science.

Non-line-of-sight (NLOS) imaging methods use light scattered from multiple surfaces to reconstruct images of scenes that are hidden by another object. This Perspective summarizes existing NLOS imaging techniques and discusses which directions show most promise for future developments.

As the COVID-19 pandemic continues, mathematical epidemiologists share their views on what models reveal about how the disease has spread, the current state of play and what work still needs to be done.

Time-periodic fields provide a versatile platform for inducing non-equilibrium topological phenomena in quantum systems. We discuss how such fields can be used for topological band structure engineering, and the conditions for observing robust topological behaviour in a many-body setting.

This Expert Recommendation provides a guide to identifying practical situations where the likelihood ratio test statistic cannot be approximated by a χ² distribution and proposes adequate solutions.

Plasmon-enhanced Raman spectroscopy (PERS) is a highly sensitive technique that can provide molecular fingerprint information. This Technical Review discusses the fundamental principles, advantages and limitations of PERS, key issues in using PERS and interpreting results, and state-of-the-art applications in materials characterization, bioanalysis and the study of surfaces.

Nine researchers, editors and science communicators share their views about the barriers that Asian scientists encounter in publishing their work and becoming more visible on the international level.

Due to their atomic structure, ultracold alkaline-earth atoms are well suited for quantum simulation and the study of quantum many-body physics. This Perspective overviews the ways to control the interactions between atoms and discusses the new physics that could be uncovered.

Active matter consists of energy-consuming units, which self-propel, exert forces on their neighbours and act collectively, resulting in emergent non-equilibrium behaviour. This Review surveys computational models that describe a wide range of active systems, from synthetic microswimmers to animal herds.

Metadynamics is a technique to enhance the probability of observing rare events, such as chemical reactions and phase transitions, in molecular dynamics simulations. This Technical Review surveys the technique, addressing the critical issues that are met in practical applications.

Optical microscopy is limited to shallow in vivo imaging depths owing to the exponential extinction of single-scattered waves by multiple light scattering. In this Review, we survey methodologies for deep optical imaging that maintain microscopic resolution by making deterministic use of multiple-scattered waves.

Substantial progress has been made towards making fusion a source of commercial energy. One challenge is the damage that filamentary plasma eruptions cause to plasma-facing components. This Perspective summarizes what is understood about these eruptions and strategies for controlling them.

The integration of gate-defined quantum dots with superconducting resonators results in a hybrid architecture that holds promise for quantum information processing. This Review discusses recent experimental results in the field, including the achievement of strong coupling between single microwave photons and the charge and spin degrees of freedom, and examines the underlying physics.

Cosmological computer simulations of galaxy formation emerged as the primary tool to study structure formation in the Universe. This Technical Review describes the main techniques and ingredients of such simulations and their application to develop and constrain galaxy formation theories.

Cilia are hair-like organelles that enable cellular locomotion. This Review considers cilia from a dynamical systems perspective, discussing the nonlinear oscillations seen in the single cilia of microorganisms and the emergent topological phenomena seen in the ciliary arrays of animals.