Earbud biosensors provide continuous monitoring of brain activity and lactate levels

15 Nov 2023

Simultaneous sensing Flexible electrochemical and electrophysiological sensors are attached to in-ear headphones, or earbuds, via a stamp-like surface. Once the earbuds are inserted in the ear canal, the sensors simultaneously monitor brain states and exercise levels. (Courtesy: Erik Jepsen/University of California San Diego)

Earbuds equipped with biosensors can continuously measure the electrical activity of the brain and levels of the sweat secretion lactate. The device represents a potential new wearable sensing technology for detection and monitoring of neurogenerative diseases or long-term health monitoring.

Developed by a multidisciplinary team of engineers at the Center for Wearable Sensors at the UC San Diego Jacobs School of Engineering, the earbud sensors wirelessly transmit the recorded data to a smartphone or laptop computer for visual display and analysis.

 

A nanoscale device produces a stream of chiral single photons

06 Oct 2023 Isabelle Dumé

Formed within wells indented into the stack of two different layered materials (a monolayer semiconductor and an anti-ferromagnetic crystal), the chiral quantum light emissions rise up out of the material and could be used for quantum information and communication applications. (Courtesy: Los Alamos National Laboratory)

A new nanoscale device based on stacks of two-dimensional materials can not only generate a stream of single photons but can also control their chirality, or circular polarization, without the need for an applied magnetic field. Since manipulating a photon’s polarization state is a way to encode information in it, the advance could be important for quantum technologies, according to the researchers at the Los Alamos National Laboratory in the US who developed it.

 

Single-molecule makes a sensitive pressure and force sensor

15 Nov 2023 Isabelle Dumé

Flopping around: A drawing of the bullavene molecule and the rearrangements it undergoes as it changes into its different possible shapes, or isomers. (Courtesy: Wikipedia/public domain image)

Researchers in Australia have detected and controlled changes to the shape of a single molecule in response to an applied mechanical force. The feat could enable the development of miniaturized implantable pressure sensors and accelerometers for the electronics industry.

 

Neutral-atom quantum computers are having a moment

09 Nov 2023

All systems go: A beam of laser light in Jeff Thompson's lab at Princeton University, where he and his colleagues recently demonstrated a new way of erasing errors in a neutral-atom quantum computer. (Courtesy: Frank Wojciechowski)

In the race for the quantum computing platform of the future, neutral atoms have been a bit of an underdog. While quantum bits (qubits) based on neutral atoms have several attractive characteristics, including the ease of scaling up qubit numbers and performing operations on them in parallel, most attention has focused on rival platforms. Many of the largest machines are built with superconducting qubits, including those developed at IBM, Google, Amazon, and Microsoft. Other companies have opted for ions, like Honeywell and IonQ, or photons, like Xanadu.

 

Weak measurement lets quantum physicists have their cake and eat it

20 Nov 2023 Raman Choudhary

Certified entangled In this entanglement certification scheme involving weak certification and reversal measurements, two parties (traditionally known as Alice and Bob) sitting in their respective laboratories share a potentially entangled pair of systems in the shared state |Ψi⟩. In the certification step, they subject their local systems to weak certification measurements to obtain statistics. In each run, they obtain outputs (±1) and the corresponding output state |Ψm⟩ that still has some entanglement. After passing the certification test, the post-measurement state |Ψm⟩ is subjected to reversal measurements in the last step to obtain the original state |Ψf⟩ = |Ψi⟩ probabilistically. (Courtesy: Recovering quantum entanglement after its certification 2003 Science Advances 9 40 doi:10.1126/sciadv.adi5261)

 

Shoot-through proton FLASH: a robust approach to brain tumour treatment

22 Nov 2023 Tami Freeman

Plan comparisons Example dose and LETD distributions for clinical IMPT and shoot-through proton FLASH plans for two patients with brain tumours. (Courtesy: CC BY 4.0/Phys. Med. Biol. 10.1088/1361-6560/ad0280)

Proton therapy is an increasingly popular cancer treatment that offers superior dose shaping to conventional photon radiotherapy. This high-precision dose delivery, however, means that target margins are needed to account for range uncertainties, exposing more healthy tissue to radiation. In addition, uncertainties in linear energy transfer (LET) and relative biological effectiveness (RBE) at the end of the beam range can increase irradiation of healthy tissue behind the target.

 

Flexible X-ray detectors line up for medical imaging and radiotherapy

23 Nov 2023 Tami Freeman

Tissue-equivalent detector Flexible X-ray detectors based on organic semiconductors modified with high-Z heteroatoms could prove ideal for a wide range of medical imaging, radiotherapy and dosimetry applications. (Courtesy: Prabodhi Nanayakkara)

X-ray detectors play a key role in a wide range of medical applications, including diagnostic imaging, radiotherapy dosimetry and personal radiation protection. Many of these applications require large-area detectors that can flexibly conform to curved surfaces. But most commercial X-ray detectors are stiff, power-hungry and expensive to fabricate into large areas.

One alternative is organic semiconductors, which can be used to create large-area optoelectronic devices via environmentally friendly, low-cost manufacturing techniques. Organic materials, however, exhibit low X-ray attenuation, resulting in detectors with low sensitivity. A team headed up at the University of Surrey’s Advanced Technology Institute aims to solve this problem. By adding small amounts of high-Z elements to an organic semiconductor, the researchers created organic X-ray detectors with high sensitivity and high flexibility.

 

New chip architecture offers hope for scaling up superconducting qubit arrays

17 Nov 2023 Avishma Lasrado

Multichip module: A photograph showing the qubit chip (outlined in red) stacked on the single flux quantum (SFQ) chip (outlined in blue). (Courtesy: Adapted from "Single Flux Quantum-Based Digital Control of Superconducting Qubits in a Multichip Module", PRX Quantum 4, 030310 https://doi.org/10.1103/PRXQuantum.4.030310)

Scientists in the US have introduced an ingenious new quantum chip architecture that significantly reduces disturbances caused by the signals used to control superconducting quantum bit (qubit) circuits. Led by Chuan Hong Liu and Robert McDermott of the University of Wisconsin, the team showed that the new multichip module (MCM) reduces gate errors by nearly a factor of 10 compared to earlier designs that used the same control system, making it a viable competitor to standard technologies.

 

Biomedical ethicists call for rules governing human research in commercial spaceflight

23 Nov 2023 Hamish Johnston

Our guest in this episode of the Physics World Weekly podcast is the biomedical ethicist Vasiliki Rahimzadeh, who along with colleagues has called for the commercial space industry to adopt ethical policies and best practices for research done on humans during space flights.

Rahimzadeh, who is at Baylor College of Medicine in the US, explains that as well as minimizing risks to paying astronauts who take part in experiments, an ethical framework should also ensure that private spaceflight – which is still the purview of the elite – benefits society as a whole.

 

New telecoms satellites will degrade our view of the cosmos

16 Nov 2023 Hamish Johnston

Astronomers are becoming increasingly concerned about the growing number of satellites that are lighting up the night sky by reflecting sunlight to Earth. In 2022, the prototype communications satellite BlueWalker 3 was launched and it is now the brightest commercial satellite ever – outshining almost every star in the sky. And to make matters worse, communications satellites like BlueWalker 3 broadcast microwave signals that can interfere with radio astronomy.

 

Top-cited work from North America recognized by IOP Publishing

17 Nov 2023 Michael Banks

This is the first year that IOP has recognised North America, having already published top-cited awards for China and India (courtesy: iStock/Igor-Kutyaev)

Almost 130 articles from researchers in North America have been recognized with a top-cited award for 2023 from IOP Publishing, which publishes Physics World. The papers received over 15400 citations in total and represent the top 1% of the most-cited articles that have been published by IOP Publishing between 2020 and 2022 with corresponding authors from North America.

This is the first year that IOP has recognised North America, having previously published top-cited awards for China and India. The papers were identified using data from Clarivate’s Web of Science database and cover 10 categories including biosciences, machine learning and reviews.

WHEN CHITIN IS CANCEROUS TO HUMAN?

 There is currently no evidence to suggest that chitin itself is carcinogenic to humans. Chitin is a naturally occurring polysaccharide found in the exoskeletons of insects and crustaceans, as well as in the cell walls of fungi. It is widely used in various industries, including food, pharmaceuticals, and cosmetics, without any known carcinogenic effects.

IS CHITIN IN THE FORM OF NANOPARTICLES CANCEROUS FOR HUMANS?

 

IS CHITIN IN THE FORM OF NANOPARTICLES CANCEROUS FOR HUMANS?

Chitin itself is not considered to be carcinogenic for humans. However, it is important to note that the toxicity of chitin nanoparticles can vary depending on their size, shape, and surface characteristics. Some studies have suggested that certain types of nanoparticles, including chitin nanoparticles, may have potential cytotoxic effects. However, more research is needed to fully understand the potential health risks associated with chitin nanoparticles. As with any potential exposure to nanoparticles, it is advisable to follow safety guidelines and take necessary precautions when handling or working with them.

There is currently no evidence to suggest that chitin in the form of nanoparticles is carcinogenic to humans. Chitin is a naturally occurring polysaccharide found in the exoskeletons of insects, crustaceans, and fungi. It is commonly used in various industries, including biomedical applications, due to its biocompatibility and biodegradability. However, like any other material, the safety of chitin nanoparticles will depend on factors such as size, shape, surface charge, and dosage. Further research and studies are always necessary to ensure the safety of any new material.

KONSTANTINOS P. TSIANTIS 20/11/2023

 

The new superconducting nanowire single-photon detector has 400,000 pixels

16 Nov 2023

Cosmic image: illustration of how, with further improvements, the new SNSPD could be used to observe astronomical objects. (Courtesy: S Kelley/NIST/Pixaby)

The highest resolution to date in a superconducting nanowire single-photon detector (SNSPD) camera has been claimed by researchers in the US. Designed by a team at the National Institute of Standards and Technology (NIST) and NASA’s Jet Propulsion Laboratory, the camera offers a pixel count some 400 times higher than other state-of-the-art designs, without sacrificing any of their advantages.

 

New telecoms satellites will degrade our view of the cosmos

16 Nov 2023 Hamish Johnston

Astronomers are becoming increasingly concerned about the growing number of satellites that are lighting up the night sky by reflecting sunlight to Earth. In 2022, the prototype communications satellite BlueWalker 3 was launched and it is now the brightest commercial satellite ever – outshining almost every star in the sky. And to make matters worse, communications satellites like BlueWalker 3 broadcast microwave signals that can interfere with radio astronomy.

 

Evidence emerges for a carbon-rich ocean on Europa

26 Sep 2023

Icy surface: Jupiter's moon Europa, as seen by JWST’s NIRCam. Tara Regio is the white area in the centre. (Courtesy: NASA, ESA, CSA, Gerónimo Villanueva/NASA-GSFC, Samantha K Trumbo/Cornell University).

Planetary scientists in the US have traced carbon on the surface of Jupiter’s moon Europa to the icy ocean beneath it, revealing new information about the ocean’s nature and origin. The discovery raises astrobiologists’ hopes that the carbon, which exists in the form of carbon dioxide, could stem from biological processes taking place under the ice. However, a search for water plumes bursting out of Europa’s surface came up empty, and scientists involved in the observations say that better measurements will be needed to distinguish between biological and geological sources of carbon.

ByDAVID NIELD

(koto_feja/E+/Getty Images)

 

Physicists Discover a New State of Matter Hidden in The Quantum World

PHYSICS24 June 2023

You're familiar with the states of matter we encounter daily – such as solid, liquid, and gas – but in more exotic and extreme conditions, new states can appear, and scientists from the US and China just found one.

They're calling it the chiral bose-liquid state, and as with every new arrangement of particles we discover, it can tell us more about the fabric and the mechanisms of the Universe around us – and in particular, at the super-small quantum scale.

States of matter describe how particles can interact with one another, giving rise to structures and various ways of behaving. Lock atoms in place, and you have a solid. Allow them to flow, you have a liquid or gas. Force charged partnerships apart, you have a plasma.

Cool Copper Collider Most Environmentally Friendly among Higgs Factory Designs Finds study

15 Nov 2023

Cool runnings: an analysis finds that the US-based Cool Copper Collider would, if built, have the lowest overall carbon footprint compared to rival Higgs factory designs. (Courtesy: Emilio Nanni/ SLAC National Accelerator Laboratory)

Changes to the operation of a planned Higgs factory could significantly improve its energy efficiency, but construction will have the biggest impact on the facility’s overall carbon footprint. That is the conclusion of an analysis of the potential environmental impact of the Cool Copper Collider (C3) – a proposed successor to CERN’s Large Hadron Collider (LHC).

 

Electrons accelerated by firing lasers into nanophotonic cavities

25 Oct 2023

Tiny device: photograph of the microchip containing the Friedrich-Alexander University dielectric laser accelerator. A one cent euro coin is shown for comparison. (Image: FAU/Laser Physics, Stefanie Kraus, Julian Litzel)

Laser-driven particle accelerators on silicon chips have been created by two independent research groups. With further improvements, such dielectric laser accelerators could be used in medicine and industry – and could even find application in high-energy particle physics experiments.

 

Organic molecule from trees excels at seeding clouds, CERN study reveals

05 Oct 2023

Cloud expert: Lubna Dada and colleagues have found that sesquiterpenes have the potential to play an important role in cloud formation. (Courtesy: Paul Scherrer Institute/Markus Fischer)

A family of organic compounds released by trees could play a far greater role in cloud formation than previously thought. That is the conclusion of Lubna Dada at Switzerland’s Paul Scherrer Institute and an international team, who say that their insights could play a crucial role in predicting the future of Earth’s climate.

When trees come under stress, they release organic molecules that react with ozone, nitrate radicals and other compounds in the atmosphere. These reactions create tiny solid particles called ultra-low-volatility organic compounds (ULVOCs).

 

The three-qubit computing platform is made from electron spins

28 Oct 2023

Multiple qubit platform: In this diagram, an STM tip coated with iron (top) operates the sensor spin qubit. Also shown are the remote spin qubits, which are aligned by the magnetic fields of nearby iron atoms. (Courtesy: Institute for Basic Science)

A quantum computing platform that is capable of the simultaneous operation of multiple spin-based quantum bits (qubits) has been created by researchers in South Korea. Designed by Yujeong Bae, Soo-Hyon Phark, Andreas Heinrich, and colleagues at the Institute for Basic Science in Seoul, the system is assembled atom-by-atom using a scanning tunneling microscope (STM).

 

NASA’s Mars Sample Return mission slammed by independent review panel

20 Oct 2023

Under fire: the Mars Sample Return mission would bring back Martian samples that had been collected by NASA’s Perseverance Rover (courtesy: NASA/JPL-Caltech)

The future of NASA’s next flagship mission to Mars has been put in doubt following a scathing report from the agency’s Independent Review Board. It concludes that the Mars Sample Return mission, which is set to be launch in 2028, faces a series of technical problems, a runaway budget as well as a dubious launch timetable.

NASA and its collaborator on the project — the European Space Agency – regard the mission as a “critical next step” in plans to explore Mars. Part of that plan involves NASA’s Perseverance Rover, which landed on Mars in 2020. It has already collected a series of Martian samples and deposited them on the surface. They would then be collected by a separate mission – the MSR – and returned to Earth.

 

Aerosol geoengineering will not stop the Antarctic ice sheet from melting, simulations suggest

31 Aug 2023

Running out of time: geoengineering will not prevent the collapse of the West Antarctic Ice Sheet, study suggests. (Courtesy: Shutterstock Bernhard Staehli)

Artificially dimming the Sun by injecting aerosols into Earth’s atmosphere may help to delay a significant consequence of climate change in Antarctica, but not stop it — researchers in Switzerland and the UK have revealed. Through new simulations, a team led by Johannes Sutter at the University of Bern has showed that the collapse of the West Antarctic Ice Sheet (WAIS) can only be avoided if we eliminate global emissions of greenhouse gases as quickly as possible.

 

Pairs of rogue planets found wandering in the Orion Nebula

12 Oct 2023

Going rogue: Jupiter-mass planets have previously been found floating freely without a parent star, but not in such large numbers and never as binary pairs until the current study. (Courtesy: NASA/JPL-Caltech)

More than 500 free-floating planetary-mass objects have been discovered wandering through the Orion Nebula thanks to new observations by the James Webb Space Telescope (JWST). Most bizarrely, about 40 of these newfound objects in the nebula’s Trapezium Cluster exist in wide binary pairs, confounding expectations about how these so-called “rogue planets” form.

Free-floating planetary-mass objects that do not orbit a star have been discovered in star-forming regions before, but never in the numbers seen by the JWST’s Near-Infrared Camera (NIRCam). These objects are visible because they are still young and glowing with the heat of their formation. Over time, they will cool and fade from view.

 

Seismic waves reveal complexities in Mars’ mantle

14 Nov 2023

Complex interior: illustration showing the two different layers of the Martian mantle between the core and crust. Also shown is how the layers affect seismic waves detected by InSight. (Courtesy: IPGP-CNES)

Mars’ mantle is divided into a partially molten outer layer and a fully molten, silicon-rich layer that lies closer to the planet’s core. This discovery was made by two independent teams and challenges the previous view that the mantle – which lies between the Martian crust and core – has a uniform composition and structure. The new analyses used seismic data from NASA’s InSight Mars lander and could help shape our understanding of how the red planet formed and evolved.

Some of the seismic waves studied were created by meteorites impacting the planet. The waves will have traveled deep within Mars before they reach InSight’s seismometer, and studying them provides important information about the Martian interior.

 

Multidisciplinary collaboration opens the way to strategic innovation in wireless technology

18 Sep 2023 Sponsored by BAE Systems Digital Intelligence

BAE Systems Digital Intelligence offers early-career physicists the opportunity to deliver game-changing technology innovations within its Wireless Products team

Into the field The Wireless Products team at BAE Systems Digital Intelligence uses digital signal processing to manipulate the electromagnetic world, with an emphasis on advanced software-defined radio (SDR) technologies. (Courtesy: BAE Systems)

Lancaster University physics graduate Ben is a member of the Wireless Products team at BAE Systems Digital Intelligence, a company that employs more than 4500 digital, cyber and intelligence experts to help government, military and commercial customers defend against advanced threats. He talked to Physics World about the joys of working at the cutting edge in electronics and digital signal processing while applying his mathematics and physics skills to diverse engineering problems.

All-electric organic laser is a first

 

All-electric organic laser is the first

14 Nov 2023 Isabelle Dumé

A schematic of the device. The organic LED is at the top – organic layers in between contacts. A voltage is applied to it, injecting charges and generating light that then excites the organic laser (lower half of figure). The organic laser contains a grating, applies feedback and also diffracts some of the laser light out of the structure – the yellow arrow in the figure. (Courtesy: Kou Yoshida)

Researchers at St Andrews University in Scotland have made the first organic semiconductor laser that does not require a separate light source to operate – something that had proved extremely challenging. The new all-electrically-driven laser is more compact than previous devices and operates in the visible region of the electromagnetic spectrum. As such, its developers say it might find use in applications such as sensing and spectroscopy.

 

Petition calls on UK to save JET fusion experiment from closure

01 Nov 2023

Hot topic: For over the past decade, JET has been carrying out “ITER relevant” experiments, in anticipation of the opening of giant fusion reactor in Cadarache, France (courtesy: EUROfusion)

More than 750 people have signed a petition against the planned closure of the Joint European Torus (JET), a major fusion experiment that has been running in the UK for almost 40 years. The UK Atomic Energy Authority (UKAEA), which operates JET, plans to shut down the nuclear fusion reactor in early 2024. The petition says the closure of JET would be “a serious scientific blow” that will have a “negative impact” on the worldwide fusion community.

JET has been carrying out fusion experiments since it opened in 1984. Over the past decade or so it has been doing “ITER relevant” experiments, in anticipation of the opening of the ITER fusion reactor, which is currently being built in Cadarache, France. In 2011, for example, JET had a refit of its plasma wall to include a mixture of tungsten and beryllium tiles so that scientists can gain a better understanding for how ITER’s beryllium plasma wall will perform.

What the movie Oppenheimer can teach today’s politicians about scientific advice

13 Nov 2023 Robert P Crease

US authorities celebrated Robert Oppenheimer for developing atomic weapons but sidelined him when he wanted to advise them on their use. It’s an episode that has many lessons for us today, says Robert P Crease

Moment of reckoning Cillian Murphy (centre, at microphone) playing J Robert Oppenheimer in a scene from the 2023 movie Oppenheimer that recreates his hearing of the US Atomic Energy Commission in 1954. (Courtesy: Universal Pictures)

One of the scariest moments in Robert Oppenheimer’s career was not shown in Oppenheimer, the recent blockbuster movie. That moment occurred during the contentious hearing on his security clearance, which concerned Oppenheimer’s role on a committee to advise the US government on nuclear weapons. Ostensibly about his loyalty to America, the hearing also revealed deeper concerns about his left-wing sympathies and opposition to an early project to build a hydrogen bomb.

 

Quantum dot pioneers win Nobel Prize for Chemistry

04 Oct 2023 Michael Banks

This year's chemistry laureates. (Courtesy: III Niklas Elmehed/Nobel Prize Outreach)

The Nobel Prize for Chemistry has been won by Moungi Bawendi, Louis Brus and Alexei Ekimov for “the discovery and synthesis of quantum dots”.

Quantum dots are extremely small particles just a few atoms in size and their properties allow them to emit light at specific wavelengths. Since the 1930s physicists had known that, in theory, quantum effects could arise in nanoparticles that would give them unusual characteristics, but for decades it was difficult to create such materials in the laboratory.

 

A leaky insulating layer reduces battery lifetime

13 Nov 2023 Isabelle Dumé

Battery research team member Yaobin Xu inserts a sample into a transmission electron microscope to examine the function of a rechargeable battery. (Courtesy: Andrea Starr | Pacific Northwest National Laboratory)

The first direct measurements of thin, supposedly insulating deposits that form in ageing rechargeable lithium-ion batteries have turned up a surprising result: the deposits are not a perfect insulator after all. According to researchers at the US Department of Energy’s Pacific Northwest National Laboratory (PNNL), the solid electrolyte interphase (SEI) layer, as it is known, is instead prone to “leaking” electrons – a finding that may help scientists develop longer-lasting batteries.

 

Electrons caught going around the bend

06 Nov 2023 Isabelle Dumé

Follow the flow: Graphs showing the smooth flow of photocurrent streamlines around a microscopic structure shaped like an aeroplane wing. This electrofoil (top left) makes it possible to contort, compress and expand photocurrent streamlines in the same way that aeroplane wings (shown in silhouettes at right) contort, compress and expand the flow of air. (Courtesy: UCR/QMO Lab)

Taking inspiration from the flow of air around aeroplane wings, researchers in the US have imaged photoexcited electrons flowing around sharp bends for the first time. Because such bends are often found in integrated optoelectronic circuits, observing the electrons’ “streamlines” could lead to improvements in circuit design.

 

Evidence found for the production of tellurium in neutron star mergers

03 Nov 2023

Cataclysmic collision: It is thought that ‘rapid neutron-capture processes’ that occur during a neutron star merger could be responsible for producing heavy elements (courtesy: NSF/LIGO/Sonoma State University/A. Simonnet)

Physicists in Japan and Lithuania have found evidence that tellurium is produced in neutron star mergers. Their findings bolster the idea that neutron star mergers are responsible for most of the heavy elements in the universe.

The synthesis of heavy nuclei – those heavier than silver – is described by a set of nuclear reaction know as the “r-process” or rapid neutron-capture process.

 

European Space Agency’s Euclid mission takes its first dazzling images of the cosmos

07 Nov 2023 Michael Banks

The horsehead nebula as seen by the European Space Agency's Euclid craft (courtesy: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi; CC BY-SA 3.0 IGO)

The first full-colour images of the cosmos taken by the €1.4bn Euclid mission have been released today by the European Space Agency (ESA).

The five dazzling images show galaxies, globular clusters and nebulae in incredible detail. The image above is the iconic horsehead nebula, which lies some 1375 light-years away from Earth as part of the constellation Orion.