Physics World

Conventional particle accelerators use radio frequency cavities to push particles to high energies, but these machines are vast and expensive. Laser wakefield accelerators (LWFAs) offer a radically different approach. When an intense laser pulse travels through a plasma, it drives a rippling disturbance called a wakefield. Electrons can be trapped in this plasma wave and surf along it, being boosted to very high energies over just centimetres. However, these electrons tend to outrun the plasma w

Quantum technologies often imagine distant users – Alice and Bob – sharing entangled particles and trying to learn something about them. In principle, the most powerful measurements are global: Alice and Bob act as if their systems were in the same lab. In reality, they are usually limited to local operations and classical communication (LOCC). This means that each makes measurements locally and sends classical messages back and forth. A long standing debate is how much classical com

After more than 15 years of conflicting results, two independent measurements appear to have settled the debate over the charge radius of the proton. The new measurements, which are the most precise to date and are based on protons in normal atoms, suggest that the radius is 0.8406 femtometres (10-15 m) – very close to the measured value that initiated the controversy back in 2010. Charge radius is a measure of how far the electric charge of a particle extends into space. In protons, researchers

Almost 2000 scientists have signed an open letter criticising planned redundancies at the University of Nottingham in the UK. The signatories, which includes six Nobel laureates, call on the university to reverse its plan to reduce the number of staff members in the physics department from 71 to 51. News of the possible job losses emerged on 12 May, when 2700 Nottingham staff were sent letters saying they were at risk of redundancy as part of plans to slash more than 600 academic posts throughou

People have been using reinforced rubber for nearly a century, but we still don’t know why it’s so strong. Researchers at the University of South Florida (USF) in the US now say they may have the answer thanks to advanced molecular dynamics simulations. Their work could make it possible to design new materials that are safer and have even better mechanical properties. Reinforced rubber is made by adding a nanoparticle filler – typically carbon black or silica – to elastic polymers (elastomers).

"caption required (Courtesy of: ????)"Graduate students at Trinity College Dublin. (Courtesy: Matt Boyd/Mahoo) The impact of quantum science and technology is going to be profound, with quantum computing in particular – but also quantum sensing, simulation and communication – set to be a major driver of economic growth and sustainable development in countries around the globe. Ireland is no exception. It is already home to some of the world’s largest technology companies, many of which are heavi

"<strong>Switchable free-space skyrmions<\/strong> Researchers used a nonlinear metasurface to experimentally demonstrate that skyrmions can be switched between electric and magnetic modes in free-space toroidal terahertz light pulses. (Courtesy: Li Niu and Xueqian Zhang, Tianjin University)"Switchable free-space skyrmions Researchers used a nonlinear metasurface to experimentally demonstrate that skyrmions can be switched between electric and magnetic modes in free-space toroidal te

Analysis by physicists in China suggest that if dark matter carries even a tiny electric charge, it will generate a magnetic “hum” in Earth’s geomagnetic field. And what is more, data from existing magnetometer networks can already constrain this effect. Dark matter is one of the biggest open questions in modern physics. Astronomers infer the existence of hypothetical dark-matter particles from their gravitational influence. The invisible presence of dark matter explains why galaxies rotate too

Alfred Tennyson was “the only poet since the time of Lucretius who has taken the trouble to understand the work and tendency of the men of science” said the English biologist Thomas Huxley on the occasion of Tennyson’s burial in the Poets’ Corner of Westminster Abbey on 12 October 1892. Tennyson’s acquaintance with science and its impact on his poetry is the subject of historian and broadcaster Richard Holmes’s new book The Boundless Deep: Young Tennyson, Science and the Crisis of Belief.

Fancy some more? Check out our puzzles page. The post Quiz of the week: what technique may be able to create super-high laser intensities? appeared first on Physics World.

While LiMnxFe1-xPO4 (LMFP) cathode materials have been investigated academically for decades, they have been adopted by dominant battery manufacturers only in the past three years. What has prompted this sudden commercial interest? What market share might LMFP gain, can it outpace LFP and NMC? What are the outstanding limitations, and how might these be overcome? In this webinar, we aim to answer these questions, covering challenges ranging from the fundamental characteristics of LMFP to large-f

A single atom is one of the last places one would expect to find a gravitational wave. These ripples in spacetime are caused by movements of massive objects such as black holes, and they are typically detected using instruments that measure tiny changes in the distance between mirrors separated by kilometres.  Their home territory is on large scales, not the microscopic scale of an atom. Despite this, physicists have questioned for decades whether gravitational waves might affect how often atoms

Researchers in the US and Canda have discovered a naturally occurring “Voronoi pattern” in the Chinese money plant. Voronoi diagrams were introduced in the 1600s by French philosopher René Descartes and are named after the Russian mathematician Georgy Voronoi, who defined and studied them in the early 1900s. Voronoi diagrams are geometric patterns used to divide space into regions. The plane is divided up into tessellating polygons, known as cells, that each contain a “seed” point. Every locatio

Researchers in China have developed a new way of probing the magnetic domains within altermagnetic materials and used it to study a prominent altermagnet candidate, alpha-phase iron oxide. According to their measurements, this material shares certain properties with ferromagnets despite having a near-zero net magnetization – a fact the researchers say supports its classification as an altermagnet. In most magnetically ordered materials, the spins of atoms (that is, their magnetic moments) can ei

This episode of the Physics World Weekly podcast features an interview with Paul Howarth, who became president of the Institute of Physics (IOP) in February. The IOP is the professional body and learned society for physics in the UK and Ireland. Representing 21,000 members, it supports physicists at all stages of their careers and seeks to make physics accessible to people from all backgrounds. With a PhD in nuclear physics, Howarth has had a long career in the nuclear sector working on the Euro

Signs of an exotic atom-like system made up of a neutral meson bound to an atomic nucleus via the strong interaction have emerged in experimental data from two international collaborations. If confirmed, this hitherto unobserved system could shed light on the origins of hadron masses and provide new insights into the fundamental symmetries of quantum chromodynamics in nuclear matter. The strong interaction is one of the four fundamental forces of nature, alongside gravity, electromagnetism and t

There are two difficulty settings: choose between a 96-piece jigsaw and the 48-piece version. Image courtesy: NASA Fancy some more? Check out our puzzles page. The post Thumbs up to Artemis II: a jigsaw puzzle appeared first on Physics World.

The prestigious Cavendish Laboratory at the University of Cambridge in the UK has an iconic status in the history of science. The university’s physics department was initially based in central Cambridge. It is where Francis Crick and James Watson famously worked on the double-helix structure of the DNA molecule. Yet in 1974 – 100 years after its foundation – the Cavendish moved to a new home on the outskirts of the city. The building was built in a drab style, covered in grey-brown pebble dash,

Photonic crystal slabs are periodic structures that confine light in two dimensions while allowing it to leak in the third. Their in‑plane periodicity forces light to behave like an electron in a crystal, forming bands rather than isolated modes. These objects can host an array of novel physical phenomena, from ultra‑sharp resonances to exotic singularities such as exceptional points. Among the most intriguing are bound states in the continuum (BICs). These are modes that, despite lying in an en

Ferroelectric materials have a permanent electric dipole, an internal separation of the centres of positive and negative ionic lattices, that can be flipped by applying an electric field. They also undergo a structural change at a material dependent temperature. known as the Curie temperature, above which this dipole behaviour disappears. Despite having permanent dipoles, ferroelectrics are insulating materials. These properties make them valuable in technologies such as sensors, actuators, and