Molecular engineering and battery recycling: developing new technologies in quantum, medicine and energy

08 May 2025 Hamish Johnston

This episode of the Physics World Weekly podcast comes from the Chicago metropolitan area – a scientific powerhouse that is home to two US national labs and some of the country’s leading universities.

Physics World’s Margaret Harris was there recently and met Nadya Mason. She is dean of the Pritzker School of Molecular Engineering at the University of Chicago, which focuses on quantum engineering; materials for sustainability; and immunoengineering. Mason explains how molecular-level science is making breakthroughs in these fields and she talks about her own research on the electronic properties of nanoscale and correlated systems.

Harris also spoke to Jeffrey Spangenberger who leads the Materials Recycling Group at Argonne National Laboratory, which is on the outskirts of Chicago. Spangenberger talks about the challenges of recycling batteries and how we could make it easier to recover materials from batteries of the future. Spangenberger leads the ReCell Center, a national collaboration of industry, academia, and national laboratories advancing recycling technologies along the entire battery life cycle.

FROM PHYSICSWPRLD.COM  12-05-2025

 

Quantum twisting microscope measures phasons in cryogenic graphene

05 May 2025 Anna Demming

Carbon layers Artist’s impression of two graphene layers before a twist is applied. (Courtesy: Shutterstock/Rost9)

By adapting their quantum twisting microscope to operate at cryogenic temperatures, researchers have made the first observations of a type of phonon that occurs in twisted bilayer graphene. These “phasons” could have implications for the electron dynamics in these materials.

Graphene is a layer of carbon just one atom thick and it has range of fascinating and useful properties – as do bilayer and multilayer versions of graphene. Since 2018, condensed-matter physicists have been captivated by the intriguing electron behaviour in two layers of graphene that are rotated relative to each other.

 

Bilayer optical lattices could unravel the secret of high-temperature superconductivity

14 Apr 2025 Yash Wath 

Diagram showing the bilayer geometry Δ represents the potential energy offset between the two layers; J_∥ and J_⊥ are the intra-layer and interlayer magnetic coupling energy respectively; and t_∥ represents the intra-layer atom hopping energy. (Courtesy: Henning Schlömer and colleagues)

A proposed experiment that would involve trapping atoms on a two-layered laser grid could be used to study the mechanism behind high-temperature superconductivity. Developed by physicists in Germany and France led by Henning Schlömer the new techniques could revolutionize our understanding of high-temperature superconductivity.

Superconductivity is a phenomenon characterized by an abrupt drop to zero of electric resistance when certain materials are cooled below a critical temperature. It has remained in the physics zeitgeist for over a hundred years and continues to puzzle contemporary physicists. While scientists have a good understanding of “conventional” superconductors (which tend to have low critical temperatures), the physics of high-temperature superconductors remains poorly understood. A deeper understanding of the mechanisms responsible for high-temperature superconductivity could unveil the secrets behind macroscopic quantum phenomena in many-body systems.

Mimicking real crystalline materials

 

Tiny sensor creates a stable, wearable brain–computer interface

15 Apr 2025 Tami Freeman

Microscale brain sensor The tiny sensor enables thought control of external devices, even during intense motion. (Courtesy: W Hong Yeo)

Brain–computer interfaces (BCIs) enable the flow of information between the brain and an external device such as a computer, smartphone, or robotic limb. Applications range from use in augmented and virtual reality (AR and VR) to restoring function to people with neurological disorders or injuries.

Electroencephalography (EEG)-based BCIs use sensors on the scalp to noninvasively record electrical signals from the brain and decode them to determine the user’s intent. Currently, however, such BCIs require bulky, rigid sensors that prevent use during movement and don’t work well with hair on the scalp, which affects the skin–electrode impedance. A team at Georgia Tech’s WISH Center has overcome these limitations by creating a brain sensor that’s small enough to fit between strands of hair and is stable even while the user is moving.

Loop quantum cosmology may explain smoothness of cosmic microwave background

 

Loop quantum cosmology may explain the smoothness of the cosmic microwave background

09 May 2025 Sponsored by EPL

Repulsive gravity at the quantum scale would have flattened out inhomogeneities in the early universe

First light: The cosmic microwave background, as imaged by the European Space Agency’s Planck mission. (Courtesy: ESA and the Planck Collaboration)

In classical physics, gravity is universally attractive. At the quantum level, however, this may not always be the case. If vast quantities of matter are present within an infinitesimally small volume – at the centre of a black hole, for example, or during the very earliest moments of the universe – spacetime becomes curved at scales that approach the Planck length. This is the fundamental quantum unit of distance, and is around 1020 times smaller than a proton.

In these extremely curved regions, the classical theory of gravity – Einstein’s general theory of relativity – breaks down. However, research on loop quantum cosmology offers a possible solution. It suggests that gravity, in effect, becomes repulsive. Consequently, loop quantum cosmology predicts that our present universe began in a so-called “cosmic bounce”, rather than the Big Bang singularity predicted by general relativity.

In a recent paper published in EPL, Edward Wilson-Ewing, a mathematical physicist at the University of New Brunswick, Canada, explores the interplay between loop quantum cosmology and a phenomenon sometimes described as “the echo of the Big Bang”: the cosmic microwave background (CMB). This background radiation pervades the entire visible universe, and it stems from the moment the universe became cool enough for neutral atoms to form. At this point, light could suddenly travel through space without being continually scattered by the plasma of electrons and light nuclei that existed before. This freshly liberated light makes up the CMB, so studying it offers clues to the early universe.

 

Abnormal ‘Arnold’s tongue’ patterns appear in a real oscillating system

22 Apr 2025 Isabelle Dumé

Synchronization studies: When the experimenters mapped the laser’s breathing frequency intensity in the parameter space of pump current and intracavity loss (left), unusual features appeared. The areas contoured by blue dashed lines correspond to strong intensity, and represent the main synchronization regions. (right) Synchronization regions extracted from this map highlight their leaf-like structure. (Courtesy: DOI: 10.1126/sciadv.ads3660)

Abnormal versions of synchronization patterns known as “Arnold’s tongues” have been observed in a femtosecond fibre laser that generates oscillating light pulses. While these unconventional patterns had been theorized to exist in certain strongly driven oscillatory systems, the new observations represent the first experimental confirmation.

Scientists have known about synchronization since 1665, when Christiaan Huygens observed that pendulums placed on a table eventually begin to sway in unison, coupled by vibrations within the table. It was not until the mid-20th century, however, that a Russian mathematician, Vladimir Arnold, discovered that plotting specific parameters of such coupled oscillating systems produces a series of tongue-like triangular shapes.

 

The mechanics behind rose petal shapes revealed

03 May 2025 Michael Banks

A rosy outlook: researchers have found that rose petal growth is all about geometric frustration (courtesy: CC BY SA Georges Seguin)

Roses have been cultivated for thousands of years and are admired for their beauty. Despite their use in fragrance, skincare, and even teas and jams, there are some things we still don’t know about these symbolic flowers.

And that includes the physical mechanism behind the shape of rose petals.

The curves and curls of leaves and flower petals arise due to the interplay between their natural growth and geometry.

Uneven growth in a flat sheet, in which the edges grow quicker than the interior, gives rise to strain. In plant leaves and petals, for example, this can result in a variety of shapes, such as saddle and ripple shapes.

 

Euclid mission spots 26 million galaxies in first batch of survey data

19 Mar 2025 Michael Banks

Deep field: An area of Euclid’s Deep Field South featuring galaxies in a variety of shapes and colours (courtesy: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre, E. Bertin, G. Anselmi)

The European Space Agency (ESA) has released the first batch of survey data from its €1.4bn Euclid mission. The release includes a preview of its “deep field,” where in just one week of observations, Euclid already spotted 26 million galaxies and many transient phenomena such as supernovae and gamma-ray bursts. The dataset is published along with 27 scientific papers that will be submitted to the journal Astronomy & Astrophysics.

The dataset also features a catalogue of 380,000 galaxies detected by artificial intelligence or “citizen science” efforts. These include those with spiral arms, central bars, and “tidal tails,” which indicate merging galaxies.

 

Superfluid phase spotted in molecular hydrogen for the first time

07 Apr 2025 Isabelle Dumé

Ultracold lab: To demonstrate superfluidity in molecular hydrogen, researchers at the University of British Columbia, RIKEN and Kanazawa University confined the molecules within a nanodroplet of helium, then embedded a methane molecule within the hydrogen molecules (left). By shining a laser beam on the methane (right), they set it rotating, and measurements of the rotation led them to identify the onset of superfluidity in hydrogen. (Courtesy: Susumu Kuma, RIKEN)

An international team led by chemists at the University of British Columbia (UBC), Canada, has reported strong experimental evidence for a superfluid phase in molecular hydrogen at 0.4 K. This phase, theoretically predicted in 1972, had only been observed in helium and ultracold atomic gases until now, and never in molecules. The work could give scientists a better understanding of quantum phase transitions and collective phenomena. More speculatively, it could advance the field of hydrogen storage and transportation.

Superfluidity is a quantum mechanical effect that occurs at temperatures near absolute zero. As the temperatures of certain fluids approach this value, they undergo a transition to a zero-viscosity state and begin to flow without resistance—behaviour that is fundamentally different from that of ordinary liquids.

 

Microwaves slow down chemical reactions at low temperatures

16 Apr 2025

Molecular reactant Ball-and-stick model of carbon monoxide. The rate at which the molecule reacts with helium ions can be controlled using microwaves. (Courtesy: Benjah-bmm27)

Through new experiments, researchers in Switzerland have tested models of how microwaves affect low-temperature chemical reactions between ions and molecules. Through their innovative setup, Valentina Zhelyazkova and colleagues at ETH Zurich showed for the first time how the application of microwave pulses can slow down reaction rates via nonthermal mechanisms.

Physicists have studied chemical reactions between ions and neutral molecules for some time. At close to room temperature, classical models can closely predict how the electric fields emanating from ions will induce dipoles in nearby neutral molecules, allowing researchers to calculate these reaction rates with impressive accuracy.

 

Retinal stimulation reveals colour never before seen by the human eye

22 Apr 2025 Tami Freeman

Retinal stimulation reveals colour never before seen by the human eye, 22 Apr 2025, Tami Freeman Oz's principle for stimulating the human retina. Novel technique elicits colour beyond the natural range of human vision. Courtesy: Fong et al. Sci. Adv. 10.1126/sciadv.adu1052

Fullscreen Player Information About Brightcove A new retinal stimulation technique called Oz enabled volunteers to see colours beyond human vision's natural range. Developed by researchers at UC Berkeley, Oz works by stimulating individual cone cells in the retina with targeted microdoses of laser light, while compensating for the eye’s motion.

 

The brain region used for speech decoding also supports BCI cursor control

30 Apr 2025

Cursor control Left: schematic of the cursor BCI; neural activity was recorded by four 64-electrode arrays located in the left ventral precentral gyrus. Right: 3D brain reconstruction showing implanted array locations (black squares) and brain areas. (Courtesy: J. Neural Eng. 10.1088/1741 2552/add0e5)

Sending an email, typing a text message, or streaming a movie. Many of us do these activities every day. But what if you couldn’t move your muscles and navigate the digital world? This is where brain–computer interfaces (BCIs) come in.

BCIs implanted in the brain can bypass pathways damaged by illness and injury. They analyse neural signals and produce an output for the user, such as interacting with a computer.

Scientists developing BCIs have primarily focused on interpreting brain activity associated with movements to control a computer cursor. The user drives the BCI by imagining arm and hand movements, which often originate in the dorsal motor cortex. Speech BCIs have also been developed, which restore communication by decoding attempted speech from neural activity in sensorimotor cortical areas such as the ventral precentral gyrus.

 

Ultrashort electron beam sets new power record

11 Apr 2025 Isabelle Dumé

Extreme beams: Claudio Emma and Brendan O’Shea examine experimental apparatus at FACET-II in 2022. (Courtesy: Jacqueline Ramseyer Orrell/SLAC National Accelerator Laboratory)

Researchers at the SLAC National Accelerator Laboratory in the US have produced the world’s most powerful ultrashort electron beam to date, concentrating petawatt-level peak powers into femtosecond-long pulses at an energy of 10 GeV and a current of around 0.1 MA. According to officials at SLAC’s Facility for Advanced Accelerator Experimental Tests (FACET-II), the new beam could be used to study phenomena in materials science, quantum physics, and even astrophysics that were not accessible before.

High-energy electron beams are routinely employed as powerful probes in several scientific fields. To produce them, accelerator facilities like SLAC use strong electric fields to accelerate, focus, and compress bunches of electrons.

 

KATRIN sets a tighter limit on neutrino mass

16 Apr 2025

Analysing electrons: Installation of the inner electrode system of KATRIN's Main Spectrometer. (Courtesy: Markus Breig, KIT)

Researchers from the Karlsruhe Tritium Neutrino experiment (KATRIN) have announced the most precise upper limit yet on the neutrino’s mass. Thanks to new data and upgraded techniques, the new limit – 0.45 electron volts (eV) at 90% confidence – is half that of the previous tightest constraint, and marks a step toward answering one of particle physics’s longest-standing questions.

Neutrinos are ghostlike particles that barely interact with matter, slipping through the universe unnoticed. They come in three types, or flavours: electron, muon, and tau. For decades, physicists assumed all three were massless, but that changed in the late 1990s when experiments revealed that neutrinos can oscillate between flavours as they travel. This flavour-shifting behaviour is only possible if neutrinos have mass.

CERN releases plans for the ‘most extraordinary instrument ever built’

02 Apr 2025 Michael Banks

Bigger and better: the feasibility study involved examining some 100 different scenarios for the collider before landing on a ring circumference of 90.7 km. (Courtesy: CERN)

The CERN particle-physics lab near Geneva has released plans for the 15bn Swiss Francs (£13bn) Future Circular Collider (FCC), a huge 91 km circumference machine. The three-volume feasibility study, released on 31 March, calls for the giant accelerator to collide electrons with positrons to study the Higgs boson in unprecedented detail. If built, the FCC would replace the 27 km Large Hadron Collider (LHC), which will end in the early 2040s.

Work on the FCC feasibility study began in 2020, and the report examines the physics objectives, geology, civil engineering, technical infrastructure, and territorial and environmental impact. It also discusses the R&D needed for the accelerators and detectors, and the socioeconomic benefits and costs.

 

Photon collisions in dying stars could create neutrons for heavy elements

12 Apr 2025

Heavy duty A high-energy photonic jet (white and blue) blasts through a collapsing star with a black hole at its centre. The red shows the cocoon where free neutrons may be available for the r-process. (Courtesy: LANL)

Matthew Mumpower at Los Alamos National Laboratory and colleagues in the US have unveiled a model that could help explain how heavy elements are forged within collapsing stars. The team suggests that energetic photons generated by newly forming black holes or neutron stars transmute protons within ejected stellar material into neutrons, providing ideal conditions for heavy elements to form.

Astrophysicists believe that elements heavier than iron are created in violent processes such as the explosions of massive stars and the mergers of neutron stars. One way this is thought to occur is the rapid neutron-capture process (r-process), whereby lighter nuclei created in stars capture neutrons in rapid succession. However, exactly where the r-process occurs is not well understood.

 

Top-quark pairs at ATLAS could shed light on the early universe

22 Apr 2025

Top observation CERN’s ATLAS experiment has confirmed that heavy quark–antiquark pairs are created in the collision of lead ions. (Courtesy: CERN/ATLAS Collaboration)

Physicists working on the ATLAS experiment on the Large Hadron Collider (LHC) are the first to report the production of top quark–antiquark pairs in collisions involving heavy nuclei. CERN’s LHC creates a fleeting state of matter called the quark–gluon plasma by colliding lead ions. This is an extremely hot and dense soup of subatomic particles, including deconfined quarks and gluons. This plasma is believed to have filled the early universe microseconds after the Big Bang.

“Heavy-ion collisions at the LHC recreate the quark–gluon plasma in a laboratory setting,” Anthony Badea, a postdoctoral researcher at the University of Chicago and one of the lead authors of a paper describing the research. In addition to boosting our understanding of the early universe, studying the quark–gluon plasma at the LHC could also provide insights into quantum chromodynamics (QCD), the theory of how quarks and gluons interact.

 

Spectacular images of the cosmos released to celebrate Hubble’s 35 years in orbit

24 Apr 2025 Michael Banks

During Hubble’s operational life, the telescope has made nearly 1.7 million observations

A series of spectacular images of the cosmos has been released to celebrate the Hubble Space Telescope‘s 35th anniversary in space. The images include pictures of Mars, planetary nebulae, and a spiral galaxy.

Hubble was launched into low-Earth orbit in April 1990, stowed in the payload bay of the space shuttle Discovery. The telescope experienced a difficult start as its 2.4 m primary mirror suffered from spherical aberration. This fault caused the curvature of the mirror to not bring light to focus at the same point. This was fixed three years later during a daring space walk in which astronauts successfully installed the COSTAR instrument.

 

An exoplanet could be in a perpendicular orbit around two brown dwarfs

30 Apr 2025

Right angle Illustration of 2M1510 showing the orbits of the two brown dwarfs (in blue) and that of the planet (in orange). (Courtesy: ESO/L Calçada)

Astronomers in the UK and Portugal have observed the first strong evidence for an exoplanet with an orbit perpendicular to that of the binary system it orbits. Based on observations from the ESO’s Very Large Telescope (VLT), researchers led by Tom Baycroft, a PhD student at the University of Birmingham, suggest that such an exoplanet is required to explain the changing orientation in the orbit of a pair of brown dwarfs – objects that are intermediate in mass between the heaviest gas-giant planets and the lightest stars.

 

UK launches first-ever industrial materials strategy

16 Jan 2025 Michael Banks

Materials world: advanced materials are used in energy-efficient supercomputers, implantable electrotherapy devices to treat brain cancer, and carbon-neutral steel (courtesy: Shutterstock/Inozemtsev-Konstantin)

Increased collaboration between different materials research and development areas will be needed if the UK is to remain a leader in the field, according to the National Materials Innovation Strategy, which claims to be the first document to boost materials-based innovation in the UK. The strategy says failing to adopt a “clear, national strategy” for materials will hamper the UK’s ability to meet its net-zero and other sustainability goals.

Led by the Henry Royce Institute—the UK’s national institute for advanced materials—the strategy included the input of over 2000 experts in materials science, engineering, innovation, policy, and industry. It says that some 50,000 people in the UK work or contribute to the materials industry, adding about £4.4bn to the UK economy each year. Of the 2700 companies in materials innovation in the UK, 70% are registered outside of London and the South East, with 90% being small and medium-sized enterprises.

 

Layer-spintronics makes its debut

29 Apr 2025 Isabelle Dumé

Altermagnetics: Electrical current flowing in an altermagnetic bilayer CrS can become spin-polarized using an external electric field, thus paving a way towards all-electrical spintronic devices for future computing technology. (Courtesy: SUTD)

Researchers at the Singapore University of Technology and Design (SUTD) have developed a new all-electrical way of controlling spin-polarized currents. By using bilayers of recently discovered materials known as alter magnets, the researchers developed a tunable and magnetic-free alternative to current approaches—something they say could bring spintronics closer to real-world applications.

Spintronics stores and processes information by exploiting electrons' quantum spin (or intrinsic angular momentum) rather than their charge. The technology works by switching electronic spins, which can point either “up” or “down”, to perform binary logical operations in the same way electronic circuits use electric charge.

 

Photonic computer chips perform as well as purely electronic counterparts, say researchers

30 Apr 2025 Isabelle Dumé

Chip package: Lightmatter's design consists of six chips in a single package with high-speed interconnects between vertically aligned photonic tensor cores and control dies. (Courtesy: Lightmatter)

Researchers in Singapore and the US have independently developed two new types of photonic computer chips that match existing purely electronic chips in terms of their raw performance. Integrated with conventional silicon electronics, the chips could be used in energy-hungry technologies such as artificial intelligence (AI).

For nearly 60 years, the development of electronic computers proceeded according to two rules of thumb: Moore’s law (which states that the number of transistors in an integrated circuit doubles every two years) and Dennard scaling (which says that as the size of transistors decreases, their power density will stay constant).

 

Fluid electrodes make soft, stretchable batteries

01 May 2025 Isabelle Dumé

Bendy battery: Researchers at Linköping University have developed a battery that can take any shape. (Courtesy: Thor Balkhed)

Researchers at Linköping University in Sweden have developed a new fluid electrode to make a soft, malleable battery that can recharge and discharge over 500 cycles while maintaining its high performance. The device, which continues to function even when stretched to twice its length, might be used in next-generation wearable electronics.

Futuristic wearables such as e-skin patches, e-textiles, and even internal e-implants on the organs or nerves will need to conform far more closely to the contours of the human body than today’s devices can. To fulfil this requirement of being soft, stretchable, and flexible, such devices will need to be made from mechanically pliant components powered by soft, supple batteries. Today’s batteries, however, are mostly rigid. They also tend to be bulky because long-term operations and power-hungry functions such as wireless data transfer, continuous sensing, and complex processing demand plenty of stored energy.

 

Two-dimensional metals make their debut

14 Apr 2025 Isabelle Dumé

A researcher from the Chinese Academy of Sciences' Institute of Physics conducts research on two-dimensional (2D) metals in Beijing. (Courtesy: Chinese Academy of Sciences' Institute of Physics/Handout via Xinhua)

Researchers from the Institute of Physics of the Chinese Academy of Sciences have produced the first two-dimensional (2D) metal sheets. At just angstroms thick, these metal sheets could be an ideal system for studying the fundamental physics of the quantum Hall effect, 2D superfluidity and superconductivity, topological phase transitions, and other phenomena that feature tight quantum confinement. They might also be used to make novel electronic devices such as ultrathin low-power transistors, high-frequency devices, and transparent displays.