̽��ֱ�� of Cambridge - ̽��ֱ�� of Warwick

Opinion: We must balance the risks and benefits of AI

lw355 — Fri, 04 Apr 2025 15:31:31 +0000

AI will only be as good – or as bad – as the information fed into it, so we need to fix any bias that perpetuates inequality and marginalisation, says Michael Barrett.

Loneliness linked to higher risk of heart disease and stroke and susceptibility to infection

cjb250 — Fri, 03 Jan 2025 10:00:00 +0000

Researchers from the UK and China drew this conclusion after studying proteins from blood samples taken from over 42,000 adults recruited to the UK Biobank. Their findings are published today in the journal Nature Human Behaviour.

Social relationships play an important role in our wellbeing. Evidence increasingly demonstrates that both social isolation and loneliness are linked to poorer health and an early death. Despite this evidence, however, the underlying mechanisms through which social relationships impact health remain elusive.

One way to explore biological mechanisms is to look at proteins circulating in the blood. Proteins are molecules produced by our genes and are essential for helping our bodies function properly. They can also serve as useful drug targets, allowing researchers to develop new treatments to tackle diseases.

A team led by scientists at the ̽��ֱ�� of Cambridge, UK, and Fudan ̽��ֱ��, China, examined the ‘proteomes’ – the suite of proteins – in blood samples donated by over 42,000 adults aged 40-69 years who are taking part in the UK Biobank. This allowed them to see which proteins were present in higher levels among people who were socially isolated or lonely, and how these proteins were connected to poorer health.

̽��ֱ��team calculated social isolation and loneliness scores for individuals. Social isolation is an objective measure based on, for example, whether someone lives alone, how frequently they have contact with others socially, and whether they take part in social activities. Loneliness, on the other hand, is a subjective measure based on whether an individual feels lonely.

When they analysed the proteomes and adjusted for factors such as age, sex and socioeconomic background, the team found 175 proteins associated with social isolation and 26 proteins associated with loneliness (though there was substantial overlap, with approximately 85% of the proteins associated with loneliness being shared with social isolation). Many of these proteins are produced in response to inflammation, viral infection and as part of our immune responses, as well as having been linked to cardiovascular disease, type 2 diabetes, stroke, and early death.

̽��ֱ��team then used a statistical technique known as Mendelian randomization to explore the causal relationship between social isolation and loneliness on the one hand, and proteins on the other. Using this approach, they identified five proteins whose abundance was caused by loneliness.

Dr Chun Shen from the Department of Clinical Neurosciences at the ̽��ֱ�� of Cambridge and the Institute of Science and Technology for Brain-Inspired Intelligence, Fudan ̽��ֱ��, said: “We know that social isolation and loneliness are linked to poorer health, but we’ve never understood why. Our work has highlighted a number of proteins that appear to play a key role in this relationship, with levels of some proteins in particular increasing as a direct consequence of loneliness.

Professor Jianfeng Feng from the ̽��ֱ�� of Warwick said: "There are more than 100,000 proteins and many of their variants in the human body. AI and high throughput proteomics can help us pinpoint some key proteins in prevention, diagnosis, treatment and prognosis in many human diseases and revolutionise the traditional view of human health.

" ̽��ֱ��proteins we’ve identified give us clues to the biology underpinning poor health among people who are socially isolated or lonely, highlighting why social relationships play such an important part in keeping us healthy.”

One of the proteins produced in higher levels as a result of loneliness was ADM. Previous studies have shown that this protein plays a role in responding to stress and in regulating stress hormones and social hormones such as oxytocin – the so-called ‘love hormone’ – which can reduce stress and improve mood.

̽��ֱ��team found a strong association between ADM and the volume of the insula, a brain hub for interoception, our ability to sense what's happening inside our body – the greater the ADM levels, the smaller the volume of this region. Higher ADM levels were also linked to lower volume of the left caudate, a region involved in emotional, reward, and social processes. In addition, higher levels of ADM were linked to increased risk of early death.

Another of the proteins, ASGR1, is associated with higher cholesterol and an increased risk of cardiovascular disease, while other identified proteins play roles in the development of insulin resistance, atherosclerosis (‘furring’ of the arteries) and cancer progression, for example.

Professor Barbara Sahakian from the Department of Psychiatry at the ̽��ֱ�� of Cambridge said: “These findings drive home the importance of social contact in keeping us well. More and more people of all ages are reporting feeling lonely. That’s why the World Health Organization has described social isolation and loneliness as a ‘global public health concern’. We need to find ways to tackle this growing problem and keep people connected to help them stay healthy.”

̽��ֱ��research was supported by the National Natural Sciences Foundation of China, China Postdoctoral Science Foundation, Shanghai Rising-Star Program, National Key R&D Program of China, Shanghai Municipal Science and Technology Major Project, 111 Project, Shanghai Center for Brain Science and Brain-Inspired Technology, and Zhangjiang Lab.

Reference
Shen, C et al. Plasma proteomic signatures of social isolation and loneliness associated with morbidity and mortality. Nat Hum Behav; 3 Jan 2025; DOI: 10.1038/s41562-024-02078-1

Interactions with friends and family may keep us healthy because they boost our immune system and reduce our risk of diseases such as heart disease, stroke and type 2 diabetes, new research suggests.

More and more people of all ages are reporting feeling lonely. We need to find ways to tackle this growing problem and keep people connected to help them stay healthy

Barbara Sahakian

Noah Silliman

Person looking out through window

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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£11m semiconductor research centre could be key player in UK’s net zero mission

sc604 — Tue, 13 Feb 2024 13:24:00 +0000

Semiconductors, also known as microchips, are a key component in nearly every electrical device from mobile phones and medical equipment to electric vehicles.

They are increasingly being recognised as an area of global strategic significance due to the integral role they play in net zero, AI and quantum technology.

Co-created and delivered with industry, the REWIRE IKC is led by the ̽��ֱ�� of Bristol, in partnership with Cambridge and Warwick Universities.

̽��ֱ��IKC will accelerate the UK’s ambition for net zero by transforming the next generation of high-voltage electronic devices using wide/ultra-wide bandgap (WBG/UWBG) compound semiconductors.

̽��ֱ��project is being led by Professor Martin Kuball and his team at the ̽��ֱ�� of Bristol. Cambridge members of the IKC team include Professors Rachel Oliver, Florin Udrea and Teng Long.

̽��ֱ��centre will advance the next generation of semiconductor power device technologies and enhance the security of the UK’s semiconductor supply chain.

Compound semiconductor WBG/UWBG devices have been recognised in the UK National Semiconductor Strategy as key elements to support the net zero economy through the development of high voltage and low energy-loss power electronic technology.

They are essential building blocks for developing all-electric trains, ships and heavy goods electric vehicles, better charging infrastructure, renewable energy and High Voltage Direct Current grid connections, as well as intelligent power distribution and energy supplies to telecommunication networks and data centres.

“Power devices are at the centre of all power electronic systems and pave the way for more efficient and compact power electronic systems, reducing energy loss,” said Kuball. “ ̽��ֱ��REWIRE IKC will focus on power conversion of wind energy, electric vehicles, smart grids, high-temperature applications, device and packaging, and improving the efficiency of semiconductor device manufacture.”

Our home electrical supply is at 240 Volts, but to handle the power from offshore wind turbines, devices will have to operate at thousands of Volts. These very high voltages can easily damage the materials normally used in power electronics.

“Newly emerging ultra-wide bandgap materials have properties which enable them to handle very large voltages more easily,” said Oliver, Director of the Cambridge Centre for Gallium Nitride. “ ̽��ֱ��devices based on these materials will waste less energy and be smaller, lighter and cheaper. ̽��ֱ��same materials can also withstand high temperatures and doses of radiation, which means they can be used to enable other new electricity generation technologies, such as fusion energy.”

“ ̽��ֱ��REWIRE IKC will play a prominent role within the UK’s semiconductor strategy, in cementing the UK’s place as a leader in compound semiconductor research and development, developing IP to be exploited here in the UK, rebuilding the UK semiconductor supply chain, and training the next generation of semiconductor materials scientists and engineers,” said Professor Peter Gammon from the ̽��ֱ�� of Warwick.

Industry partners in the REWIRE IKC include Ampaire, BMW, Bosch, Cambridge GaN Devices (CGD), Element-Six Technologies, General Electric, Hitachi Energy, IQE, Oxford Instruments, Siemens, ST Microelectronics and Toshiba.

REWIRE is one of two new IKCs announced being funded by the Engineering and Physical Sciences Research Council (EPSRC) and Innovate UK, both part of UK Research and Innovation. ̽��ֱ��second IKC at the ̽��ֱ�� of Southampton will improve development and commercialisation of silicon photonics technologies in the UK.

“This investment marks a crucial step in advancing our ambitions for the semiconductor industry, with these centres helping bring new technologies to market in areas like net zero and AI, rooting them right here in the UK,” said Minister for Tech and the Digital Economy Saqib Bhatti. “Just nine months into delivering on the National Semiconductor Strategy, we’re already making rapid progress towards our goals. This isn’t just about fostering growth and creating high-skilled jobs, it's about positioning the UK as a hub of global innovation, setting the stage for breakthroughs that have worldwide impact.”

Adapted from a ̽��ֱ�� of Bristol media release.

For more information on energy-related research in Cambridge, please visit the Energy IRC, which brings together Cambridge’s research knowledge and expertise, in collaboration with global partners, to create solutions for a sustainable and resilient energy landscape for generations to come.

̽��ֱ�� ̽��ֱ�� of Cambridge is a partner in the new £11m Innovation and Knowledge Centre (IKC) REWIRE, set to deliver pioneering semiconductor technologies and new electronic devices.

Yuichiro Chino via Getty Images

Robot arms and semiconductor wafer

Yes

Problems with ‘pruning’ brain connections linked to adolescent mental health disorders

cjb250 — Mon, 24 Apr 2023 15:00:34 +0000

̽��ֱ��findings, from an international collaboration, led by researchers in the UK, China and Germany, may help explain why people are often affected by more than one mental health disorder, and may in future help identify those at greatest risk.

One in seven adolescents (aged 10-19 years old) worldwide experiences mental health disorders, according to the World Health Organization (WHO). Depression, anxiety and behavioural disorders, such as attention deficit hyperactivity disorder (ADHD), are among the leading causes of illness and disability among young people, and adolescents will commonly have more than one mental health disorder.

Many mental health problems emerge during adolescence. Among these are disorders such as depression and anxiety, which manifest as ‘internalising’ symptoms, including low mood and worrying. Other conditions such as attention deficit hyperactivity disorder (ADHD) manifest as ‘externalising’ symptoms, such as impulsive behaviour.

Professor Barbara Sahakian from the Department of Psychiatry at the ̽��ֱ�� of Cambridge said: “Young people often experience multiple mental health disorders, beginning in adolescence and continuing – and often transforming – into adult life. This suggests that there’s a common brain mechanism that could explain the onset of these mental health disorders during this critical time of brain development.”

In a study published today in Nature Medicine, the researchers say they have identified a characteristic pattern of brain activity among these adolescents, which they have termed the ‘neuropsychopathological factor’, or NP factor for short.

̽��ֱ��team examined data from 1,750 adolescents, aged 14 years, from the IMAGEN cohort, a European research project examining how biological, psychological, and environmental factors during adolescence may influence brain development and mental health. In particular, they examined imaging data from brain scans taken while participants took part in cognitive tasks, looking for patterns of brain connectivity – in other words, how different regions of the brain communicate with each other.

Adolescents who experienced mental health problems – regardless of whether their disorder was one of internalising or externalising symptoms, or whether they experienced multiple disorders – showed similar patterns of brain activity. These patterns – the NP factor – were largely apparent in the frontal lobes, the area at the front of the brain responsible for executive function which, among other functions, controls flexible thinking, self-control and emotional behaviour.

̽��ֱ��researchers confirmed their findings by replicating them in 1,799 participants from the ABCD Study in the USA, a long-term study of brain development and child health, and by studying patients who had received psychiatric diagnoses.

When the team looked at genetic data from the IMAGEN cohort, they found that the NP factor was strongest in individuals who carried a particular variant of the gene IGSF11 that has been previously associated with multiple mental health disorders. This gene is known to play an important role in synaptic pruning, a process whereby unnecessary brain connections – synapses – are discarded. Problems with pruning may particularly affect the frontal lobes, since these regions are the last brain areas to complete development in adolescents and young adults.

Dr Tianye Jia from the Institute of Science and Technology for Brain-Inspired Intelligence, Fudan ̽��ֱ��, Shanghai, China and the Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK said: “As we grow up, our brains make more and more connections. This is a normal part of our development. But too many connections risk making the brain inefficient. Synaptic pruning helps ensure that brain activity doesn’t get drowned out in ‘white noise’.

“Our research suggests that when this important pruning process is disrupted, it affects how brain regions talk to each other. As this impact is seen most in the frontal lobes, this then has implications for mental health.”

̽��ֱ��researchers say that the discovery of the NP factor could help identify those young people at greatest risk of compounding mental health problems.

Professor Jianfeng Feng from Fudan ̽��ֱ�� in Shanghai, China, and the ̽��ֱ�� of Warwick, UK, said: “We know that many mental health disorders begin in adolescence and that individuals who develop one disorder are at increased risk of developing other disorders, too. By examining brain activity and looking for this NP factor, we might be able to detect those at greatest risk sooner, offering us more opportunity to intervene and reduce this risk.”

Funders included: the National Natural Science Foundation of China, European Union, National Institute for Health & Care Research (UK) and National Institutes of Health (NIH, USA).*

Reference
Chao Xie et al. A shared neural basis underlying psychiatric comorbidity. Nat Med; 24 Apr 2023: DOI: 10.1038/s41591-023-02317-4

*A full list of funders can be found in the paper.

Problems with the brain’s ability to ‘prune’ itself of unnecessary connections may underlie a wide range of mental health disorders that begin during adolescence, according to research published today.

Young people often experience multiple mental health disorders, beginning in adolescence and continuing – and often transforming – into adult life

Barbara Sahakian

Warren Wong

Teenager sitting near graffiti

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Social isolation may impact brain volume in regions linked to higher risk of dementia

cjb250 — Wed, 08 Jun 2022 20:00:16 +0000

“Social isolation is a serious yet underrecognized public health problem that is often associated with old age,” said study author Professor Jianfeng Feng of Fudan ̽��ֱ�� in Shanghai, China. “In the context of the COVID-19 pandemic, social isolation, or the state of being cut off from social networks, has intensified. It’s more important than ever to identify people who are socially isolated and provide resources to help them make connections in their community.”

̽��ֱ��study looked at over 460,000 people across the United Kingdom with an average age of 57 at the beginning of the study who were followed for nearly 12 years before the pandemic. Of those, almost 42,000 (9%) reported being socially isolated, and 29,000 (6%) felt lonely. During the study, almost 5,000 developed dementia.

Researchers collected survey data from participants, along with a variety of physical and biological measurements, including MRI data. Participants also took thinking and memory tests to assess their cognitive function. For social isolation, people were asked three questions about social contact: whether they lived with others; whether they had visits with friends or family at least once a month; and whether they participated in social activities such as clubs, meetings or volunteer work at least once a week. People were considered socially isolated if they answered no to at least two questions.

Of the 42,000 people with social isolation, 649 (1.55%) developed dementia, compared to 4,349 (1.03%) of those people who were not socially isolated.

After adjusting for factors including age, sex, socioeconomic status, alcohol intake and smoking, and other conditions like depression and loneliness, researchers found that socially isolated individuals had lower volume in the brain’s gray matter in various regions involved with learning and thinking. Researchers found that people who were socially isolated were 26% more likely to develop dementia than those with no social isolation. Researchers also looked at loneliness, but after adjusting, saw no strong correlation with developing dementia.

Professor Barbara Sahakian from the Department of Psychiatry at the ̽��ֱ�� of Cambridge, a study co-author, added: “People who reported high levels of social isolation were more likely to show significant differences in brain volume, in regions that we know as also associated with cognition problems and risk of dementia. This is very concerning and suggests to us that social isolation may be an early indicator of an increased risk of dementia.”

People who reported higher levels of social isolation were more likely to have lower gray matter volume in areas of the brain associated with learning and thinking. Overall, the results showed that lower gray matter volumes were associated with higher social isolation.

A limitation of the study was that participants reported fewer health conditions and were less likely to live alone than the general population, so the results may not apply to the general population.

̽��ֱ��study was a collaboration between Fudan ̽��ֱ��, the ̽��ֱ�� of Cambridge and the ̽��ֱ�� of Warwick. It was supported by the Chinese Ministry of Science and Technology, National Natural Sciences Foundation of China, the municipal government of Shanghai, ZJ Lab, Shanghai Center for Brain Science and Brain-Inspired Technology, and the Wellcome Trust.

Reference
Shen, C et al. Associations of Social Isolation and Loneliness With Later Dementia. Neurology; 8 June 2022; DOI: 10.1212/WNL.0000000000200583

Social isolation is linked to lower brain volume in areas related to cognition and a higher risk of dementia, according to research published today in Neurology. ̽��ֱ��study found that social isolation was linked to a 26% increased risk of dementia, separately from risk factors like depression and loneliness.

This is very concerning and suggests to us that social isolation may be an early indicator of an increased risk of dementia

Barbara Sahakian

Steven HWG

Elderly woman in the middle stages of Alzheimer

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

New national modelling group to provide faster, more rigorous COVID-19 predictions

sc604 — Thu, 18 Feb 2021 16:47:30 +0000

̽��ֱ��JUNIPER consortium (‘Joint UNIversities Pandemic and Epidemiological Research’) brings together leading mathematical and statistical modellers from seven UK universities and has received £3 million in funding from UK Research and Innovation (UKRI).

JUNIPER is developing and using customised models to provide predictions and estimates on key questions about the COVID-19 pandemic. These results feed regularly into SPI-M, the modelling group that provides evidence to the Scientific Advisory Group for Emergencies (SAGE) and the wider UK government.

Examples of modelling JUNIPER provides to government includes:

Understanding how new variants are spreading across the UK and developing statistical models to determine whether new variants are causing more hospitalisations or deaths.
Forecasting and providing real-time estimates of the R-value, using data from sources such as Pillar 1 and 2 testing, hospital data and mobility data. They are currently providing eight of 12 models contributing real-time R estimates that go from SPI-M to SAGE each week.
Modelling the effectiveness of different testing strategies on virus transmission and suppression, and modelling the effect of vaccinations and predicting outcomes from different scenarios of how to ease lockdown restrictions.

Professor Julia Gog, co-lead of the consortium from Cambridge’s Department of Applied Mathematics and Theoretical Physics, said: “By bringing research groups together from our seven universities we can provide predictions and estimates about the pandemic to address questions from the government with unprecedented speed. By combining the right expertise together swiftly across research teams we can now respond to questions in less than 24 hours, which might have taken a week for one team working alone. And further, being able to call upon specialist expertise combinations across multiple research groups means we can provide more robust outputs.

“In this unprecedented pandemic, modelling has been hugely important to provide evidence-based predictions and estimates at great speed. Our insights from transmission modelling are fully integrated with scientific evidence from other disciplines and feed into government decision-making.”

Professor Matt Keeling, co-lead of the consortium from the ̽��ֱ�� of Warwick, said: “We’re generating about half the models for the nowcasting that goes into SPI-M and SAGE every week. This consortium allows us to not only boost our speed and capacity, but also to continue to advance the accuracy of our models using the new data and growing knowledge from the pandemic.

“Standard epidemiological modelling tools have worked well so far, but the future with COVID-19 now demands a suite of new tools to deal with the upcoming complexities of the pandemic, such as localised regional outbreaks, growing understanding of socioeconomic differences with this disease, complexities of imperfect vaccines and the growing problem ahead with new variants. Having several teams using different models working on the same problem helps us to verify our results and makes the consortium much bigger than the sum of its parts.”

̽��ֱ��consortium is funded as part of UKRI’s COVID-19 Agile Call, which has so far invested more than £150M in over 400 projects to address the impacts of the COVID-19 pandemic.

Professor Charlotte Deane, COVID-19 Response Director at UKRI, said: “This consortium enables disease modellers to pool their expertise nationally to increase the scale, speed and quality of their models of policy options and predictions for the pandemic. They’ll provide cutting-edge evidence about the pandemic into the UK government’s decision-making.”

̽��ֱ��consortium will also proactively generate new model-based predictions and develop the necessary methodology as part of a horizon-scanning process.

̽��ֱ��consortium plan to make their models open-source, so scientists worldwide can access them and benefit.

̽��ֱ��seven universities involved in JUNIPER are Cambridge, Warwick, Exeter, Oxford, Bristol, Manchester and Lancaster Universities.

They will work closely with other organisations and research teams active on COVID-19 research including the Alan Turing Institute, the Royal Statistical Society, Health Data Research UK, Public Health England, the Royal Society’s ‘RAMP’ initiative, and the Isaac Newton Institute for Mathematical Sciences.

A new national consortium, co-led by the ̽��ֱ�� of Cambridge, will bring together mathematical modellers to produce faster, more rigorous predictions for the COVID-19 pandemic and advise UK government bodies.

Gordon Johnson from Pixabay

Connections

Yes

‘Magnetic graphene’ forms a new kind of magnetism

sc604 — Mon, 08 Feb 2021 15:21:53 +0000

̽��ֱ��researchers, led by the ̽��ֱ�� of Cambridge, were able to control the conductivity and magnetism of iron thiophosphate (FePS₃), a two-dimensional material which undergoes a transition from an insulator to a metal when compressed. This class of magnetic materials offers new routes to understanding the physics of new magnetic states and superconductivity.

Using new high-pressure techniques, the researchers have shown what happens to magnetic graphene during the transition from insulator to conductor and into its unconventional metallic state, realised only under ultra-high pressure conditions. When the material becomes metallic, it remains magnetic, which is contrary to previous results and provides clues as to how the electrical conduction in the metallic phase works. ̽��ֱ��newly discovered high-pressure magnetic phase likely forms a precursor to superconductivity so understanding its mechanisms is vital.

Their results, published in the journal Physical Review X, also suggest a way that new materials could be engineered to have combined conduction and magnetic properties, which could be useful in the development of new technologies such as spintronics, which could transform the way in which computers process information.

Properties of matter can alter dramatically with changing dimensionality. For example, graphene, carbon nanotubes, graphite and diamond are all made of carbon atoms, but have very different properties due to their different structure and dimensionality.

“But imagine if you were also able to change all of these properties by adding magnetism,” said first author Dr Matthew Coak, who is jointly based at Cambridge’s Cavendish Laboratory and the ̽��ֱ�� of Warwick. “A material which could be mechanically flexible and form a new kind of circuit to store information and perform computation. This is why these materials are so interesting, and because they drastically change their properties when put under pressure so we can control their behaviour.”

In a previous study by Sebastian Haines of the Cavendish Laboratory and the Department of Earth Sciences, researchers established that the material becomes a metal at high pressure, and outlined how the crystal structure and arrangement of atoms in the layers of this 2D material change through the transition.

“ ̽��ֱ��missing piece has remained however, the magnetism,” said Coak. “With no experimental techniques able to probe the signatures of magnetism in this material at pressures this high, our international team had to develop and test our own new techniques to make it possible.”

̽��ֱ��researchers used new techniques to measure the magnetic structure up to record-breaking high pressures, using specially designed diamond anvils and neutrons to act as the probe of magnetism. They were then able to follow the evolution of the magnetism into the metallic state.

“To our surprise, we found that the magnetism survives and is in some ways strengthened,” co-author Dr Siddharth Saxena, group leader at the Cavendish Laboratory. “This is unexpected, as the newly-freely-roaming electrons in a newly conducting material can no longer be locked to their parent iron atoms, generating magnetic moments there - unless the conduction is coming from an unexpected source.”

In their previous paper, the researchers showed these electrons were ‘frozen’ in a sense. But when they made them flow or move, they started interacting more and more. ̽��ֱ��magnetism survives, but gets modified into new forms, giving rise to new quantum properties in a new type of magnetic metal.

How a material behaves, whether conductor or insulator, is mostly based on how the electrons, or charge, move around. However, the ‘spin’ of the electrons has been shown to be the source of magnetism. Spin makes electrons behave a bit like tiny bar magnets and point a certain way. Magnetism from the arrangement of electron spins is used in most memory devices: harnessing and controlling it is important for developing new technologies such as spintronics, which could transform the way in which computers process information.

“ ̽��ֱ��combination of the two, the charge and the spin, is key to how this material behaves,” said co-author Dr David Jarvis from the Institut Laue-Langevin, France, who carried out this work as the basis of his PhD studies at the Cavendish Laboratory. “Finding this sort of quantum multi-functionality is another leap forward in the study of these materials.”

“We don’t know exactly what’s happening at the quantum level, but at the same time, we can manipulate it,” said Saxena. “It’s like those famous ‘unknown unknowns’: we’ve opened up a new door to properties of quantum information, but we don’t yet know what those properties might be.”

There are more potential chemical compounds to synthesise than could ever be fully explored and characterised. But by carefully selecting and tuning materials with special properties, it is possible to show the way towards the creation of compounds and systems, but without having to apply huge amounts of pressure.

Additionally, gaining fundamental understanding of phenomena such as low-dimensional magnetism and superconductivity allows researchers to make the next leaps in materials science and engineering, with particular potential in energy efficiency, generation and storage.

As for the case of magnetic graphene, the researchers next plan to continue the search for superconductivity within this unique material. “Now that we have some idea what happens to this material at high pressure, we can make some predictions about what might happen if we try to tune its properties through adding free electrons by compressing it further,” said Coak.

“ ̽��ֱ��thing we’re chasing is superconductivity,” said Saxena. “If we can find a type of superconductivity that’s related to magnetism in a two-dimensional material, it could give us a shot at solving a problem that’s gone back decades.”

Reference:
Matthew J. Coak et al. ‘Emergent Magnetic Phases in Pressure-Tuned van der Waals Antiferromagnet FePS3.’ Physical Review X (2021). DOI: 10.1103/PhysRevX.11.011024

Researchers have identified a new form of magnetism in so-called magnetic graphene, which could point the way toward understanding superconductivity in this unusual type of material.

Cavendish Laboratory

Illustration of the magnetic structure of FePS3

Yes

Fast-moving gas flowing away from young star’s asteroid belt may be caused by icy comet vaporisation

sc604 — Mon, 30 Nov 2020 02:00:00 +0000

Astronomers have detected fast-moving carbon monoxide gas flowing away from a young, low-mass star: a unique stage of planetary system evolution which may provide insight into how our own solar system evolved and suggests that the way systems develop may be more complicated than previously thought.

Although it remains unclear how the gas is being ejected so fast, the team of researchers, led by the ̽��ֱ�� of Cambridge, believe it may be produced from icy comets being vaporised in the star’s asteroid belt. ̽��ֱ��results have been accepted for publication in the Monthly Notices of the Royal Astronomical Society and will be presented at the Five Years After HL Tau virtual conference.

̽��ֱ��detection was made with the Atacama Large Millimetre/submillimetre Array (ALMA) in Chile, as part of a survey of young ‘class III’ stars, reported in an earlier paper. Some of these class III stars are surrounded by debris discs, which are believed to be formed by the ongoing collisions of comets, asteroids and other solid objects, known as planetesimals, in the outer reaches of recently formed planetary systems. ̽��ֱ��leftover dust and debris from these collisions absorbs light from their central stars and re-radiate that energy as a faint glow that can be studied with ALMA.

In the inner regions of planetary systems, the processes of planet formation are expected to result in the loss of all the hottest dust, and class IIII stars are those that are left with - at most - dim, cold dust. These faint belts of cold dust are similar to the known debris discs seen around other stars, similar to the Kuiper belt in our own solar system, which is known to host much larger asteroids and comets.

In the survey, the star in question, ‘NO Lup’, which is about 70% the mass of our sun, was found to have a faint, low-mass dusty disc, but it was the only class III star where carbon monoxide gas was detected, a first for this type of young star with ALMA. While it is known that many young stars still host the gas-rich planet-forming discs they are born with, NO Lup is more evolved, and might have been expected to have lost this primordial gas after its planets had formed.

While the detection of carbon monoxide gas is rare, what made the observation unique was the scale and speed of the gas, which prompted a follow-up study to explore its motion and origins.

“Just detecting carbon monoxide gas was exciting, since no other young stars of this type had been previously imaged by ALMA,” said first author Joshua Lovell, a PhD student from the Cambridge’s Institute of Astronomy. “But when we looked closer, we found something even more unusual: given how far away the gas was from the star, it was moving much faster than expected. This had us puzzled for quite some time.”

Grant Kennedy, Royal Society ̽��ֱ�� Research Fellow at the ̽��ֱ�� of Warwick, who led the modelling work on the study, came up with a solution to the puzzle. “We found a simple way to explain it: by modelling a gas ring, but giving the gas an extra kick outward,” he said. “Other models have been used to explain young discs with similar mechanisms, but this disc is more like a debris disc where we haven’t witnessed winds before. Our model showed the gas is entirely consistent with a scenario in which it’s being launched out of the system at around 22 kilometres per second, which is much higher than any stable orbital speed.”

Further analysis also showed that the gas may be produced during collisions between asteroids, or during periods of sublimation – the transition from a solid to a gaseous phase – on the surface of the star’s comets, expected to be rich in carbon monoxide ice.

There has been recent evidence of this same process in our own solar system from NASA’s New Horizons mission, when it observed the Kuiper Belt object Ultima Thule in 2019 and found sublimation evolution on the surface of the comet, which happened around 4.5 billion years ago. ̽��ֱ��same event that vaporised comets in our own solar system billions of years ago may have therefore been captured for the first time over 400 light years away, in a process that may be common around planet-forming stars, and have implications for how all comets, asteroids, and planets evolve.

“This fascinating star is shedding light on what kind of physical processes are shaping planetary systems shortly after they are born, just after they have emerged from being enshrouded by their protoplanetary disk,” said co-author Professor Mark Wyatt, also from the Institute of Astronomy. “While we have seen gas produced by planetesimals in older systems, the shear rate at which gas is being produced in this system and its outflowing nature are quite remarkable, and point to a phase of planetary system evolution that we are witnessing here for the first time.”

While the puzzle isn’t fully solved, and further detailed modelling will be required to understand how the gas is being ejected so quickly, what is sure is that this system is set to be the target of more intense follow-up measurements.

“We’re hoping that ALMA will be back online next year, and we’ll be making the case to observe this system again in greater detail,” said Lovell. “Given how much we have learned about this early stage of planetary system evolution with only a short 30-minute observation, there is still so much more that this system can tell us.”

References:
1: J.B. Lovell et al. ‘Rapid CO gas dispersal from NO Lup’s class III circumstellar disc.’ Paper presented at Five Years After HL Tau. 7-11 December 2020.

2: J.B. Lovell et al. ‘ALMA Survey of Class III stars: Early planetesimal formation and Rapid disc dispersal’, DOI: https://doi.org/10.1093/mnras/staa3335

A unique stage of planetary system evolution has been imaged by astronomers, showing fast-moving carbon monoxide gas flowing away from a star system over 400 light years away, a discovery that provides an opportunity to study how our own solar system developed.

Given how much we have learned about this early stage of planetary system evolution with only a short observation, there is still so much more that this system can tell us

Joshua Lovell

Institute of Astronomy

Artist's impression of No Lup system

Yes