Reviews & Analysis

Bound states in the continuum, for decades a theoretical curiosity, have more recently found application in nanophotonic platforms due to their high quality factors and spatial confinement. Here, the authors review recent progress in the development of active and passive photonic devices exploiting these properties.

Judicious design of metamaterials and phononic crystals permits the realization of novel localization and wave-guiding properties. Here, recent developments and strategies for applying these structures to piezoelectric energy harvesting are reviewed.

Magnetic susceptibility measurements are an integral technique used across chemistry, physics and materials science; however, while straightforward to perform, interpretation of the data is often not. Here, the authors provide a basic guide to help newcomers interpret magnetic susceptibility data outlining examples based around the Curie-Weiss law that are ideal for those wishing to learn the basics of this method.

The Microscience and Microscopy Congress (mmc) is the standout event of the microscopist’s calendar. This July, hundreds of delegates signed into a virtual mmc2021 to see the latest research and advancements in microscopy, spanning both physical and life sciences.

Here, Zanin and Olivares review the permutation patterns-based metrics used to distinguish chaos from stochasticity in discrete time series. They analyse their performance and computational cost, and compare their applicability to real-world time series.

Drawing around 60 attendees and 20 presenters to a virtual lecture room, April’s CHI-2 Photonics in Microresonators and Beyond conference explored recent progress in the use of microresonators and integrated photonic devices exhibiting second-order nonlinearity for optical frequency conversion.

This perspective presents current and future possibilities offered by space technology for testing quantum mechanics, with a focus on mesoscopic superposition of nanoparticles and the potential of interferometric and non-interferometric experiments in space.

Topological materials are extensively studied in condensed matter physics and several have been studied to the point where it is now time to ask if these unique materials have a role to play in next generation technologies. The author reviews the current status of well-characterized topological materials such as Bi₂Se₃ for electronic device applications, focusing on selected technological aspects and their promise for engineering applications.

Gravitational wave astronomy has opened the door to test general relativity and the effect of gravity in the Universe. The authors present the capabilities of an overlap between space gravitational wave detectors LISA and Taiji to constrain the Hubble constant to 0.5%, in 10 years, and what can be learned from the satellite pilot Taiji-1 launched in 2019.

Interrogating emergent nonequilibrium phenomena in light-driven quantum materials requires probing microscopic spin, charge and orbital excitations at ultrafast timescales. In this Perspective, time-resolved resonant inelastic X-ray scattering is discussed as a nascent method to investigate photoinduced states of matter.

The neutron-rich, weakly bound fluorine isotope ²⁹F has been extensively investigated theoretically, but its significance has been revived by recent experiments. The authors present the latest developments and make prediction on the electromagnetic transitions occurring in this isotope that may be observed in the near future.

Drawing around 140 attendees to the serene hills of Tuscany, Italy, February’s Gordon Research Conference (GRC) on Ultrafast Phenomena in Cooperative Systems explored recent advances in the understanding of light-induced phases of condensed matter.

Quantum information processing holds promise to achieve more secure data transfer in the current network of telecommunication fibres. Here, the authors review recent works implementing spatial division multiplexing in optical fibres and discuss their potential for quantum communication in classical networks.

Optical frequency combs were realized nearly two decades ago to support the development of the world’s most precise atomic clocks, but their versatility has since made them useful instruments well beyond their original goal, and spans across a wide variety of fundamental and applied physics in a wide range of wavelengths. Fortier and Baumann present a comprehensive review of developments in optical frequency comb technology and a view to the future with these technologies.

Magnonics involves the manipulation of spin waves in order to develop more energy efficient spintronics devices which do not rely on the movement of electronic charge. Here, the authors review the various methods designed to control magnonics with particular focus on voltage i.e. electric-field.

Quantum communication and computing is now in a data-intensive domain where a classical network describing a quantum system seems no longer sufficient to yield a generalization of complex networks methods to the quantum domain. The authors review recent progress into this paradigm shift that drives the creation of a network theory based fundamentally on quantum effects.

For both fundamental and applied sciences topological states of matter is an area of intense research and most investigations are dedicated to realizing these materials using electronic and optical methods. Here the authors review recent efforts in a third avenue of research which seeks to emulate topological states using acoustics.