School of Physics and Astronomy

In two related studies, scientists uncover surprising insights into the chemistry of giant planets.

What is metallic hydrogen?

Metallic hydrogen is believed to be the most abundant condensed material in the universe, existing deep inside giant planets such as Jupiter and Saturn.

Because metallic hydrogen can only form under immense pressures, it has been almost impossible to study in the laboratory. As a result, much of what scientists know about this material comes from theoretical models.

A new theoretical study has revealed that chemistry in the extreme environments of metallic hydrogen could be far more complex than previously thought.

Scientists used quantum mechanics to investigate how carbon, nitrogen and oxygen behave in metallic hydrogen.

Their simulations revealed that these elements can react with each other and with hydrogen to form stable, covalently bonded molecules — including CH₆, C₂H₈, C₃H₁₀, OH₃, NH₄ and CH₄OH. These compounds are known as hypermolecules, due to their unusually high hydrogen content.

Remarkably, the findings suggest that organic molecules can survive in the extreme pressures and temperatures of planets such as Jupiter and Saturn — conditions that are very different from those found on Earth.

Juno space probe

If organic molecules can survive in the extreme pressures of these planets, one might assume we could find them there.

Planets are expected to have a structure where the heaviest elements fall to the centre, forming a heavy core: for Earth this is mainly molten iron. Giant planets are mainly formed of hydrogen, and as a result of the extreme pressures deep in their interior, the hydrogen becomes first liquid, then metallic.  

Cast your mind back to 2016, when NASA’s Juno space probe arrived on Jupiter to undertake a mission to explore the planet. It was predicted that Jupiter’s core might consist of giant diamonds, rocks, ice or heavy metals. What they found was more surprising - there is no core.

In studies led by the Edinburgh team, results show that almost all elements will dissolve in metallic hydrogen, and so any heavy elements on a planet such as Jupiter are largely dissolved within the hydrogen layer.

Crucially, the study also indicates that carbon, oxygen and nitrogen may dissolve readily in metallic hydrogen. This raises new questions about the internal structure of giant planets and whether they can contain distinct rocky cores, as often assumed.

By providing the first detailed picture of possible chemical interactions in metallic hydrogen, these research studies open a new window on planetary science and high-pressure chemistry.

The late Professor Peter Higgs has gifted his Nobel Prize to the University of Edinburgh, where he first proposed an idea that would transform our understanding of the universe.

The pioneering physicist has left the internationally prestigious medal to the institution in his will, following his death aged 94 in April 2024.

It will be preserved by the University’s Centre for Research Collections and displayed at events and exhibitions, including the upcoming Higgs Lecture in 2026.

Professor Higgs is known and lauded worldwide for predicting the existence of a fundamental physical particle that came to bear his name – the Higgs boson. 

He was a researcher at the University of Edinburgh in 1964 when he predicted the particle, which enables other particles to acquire mass. 

This idea was validated by experiments almost 50 years later, at the European Organization for Nuclear Research (CERN) in Switzerland in 2012. 

The discovery was followed by the award of a Nobel Prize in Physics for Professor Higgs in 2013, which he shared with François Englert of Belgium. 

Professor Sir Peter Mathieson, Principal and Vice-Chancellor of the University of Edinburgh, said:

This generous gift will ensure that Peter Higgs’ extraordinary contributions to science will continue to inspire generations of students and researchers. We are profoundly honoured to have been entrusted with his Nobel Prize medal, an object of immense historical significance and a lasting emblem of his legacy.

Born in 1929 in Newcastle upon Tyne, Peter Higgs joined the staff of the University of Edinburgh in 1960, when he took up a lectureship at the Tait Institute of Mathematical Physics and became Personal Chair of Theoretical Physics in 1980. He retired in 1996, becoming Professor Emeritus. 

The Higgs Centre for Theoretical Physics was established by the University of Edinburgh in 2012 to recognise Professor Higgs’ achievements and create opportunities for students and researchers from around the world to formulate new theoretical concepts.

Professor Neil Turok, Higgs Chair of Theoretical Physics at the University of Edinburgh, said:

The prediction of the Higgs boson was a theoretical breakthrough, fundamental to our understanding of the laws of physics. It is fitting that Peter Higgs’ Nobel Prize medal is now preserved at Edinburgh, forming a lasting part of the University’s scientific heritage. Through our Higgs Centre for Theoretical Physics, his seminal discovery continues to serve as a springboard for those seeking answers to some of the deepest mysteries of our universe.

A plaque commemorating Professor Higgs’ legacy can be found at Roxburgh Street in Edinburgh. The installation marks the site where he first devised the theory of the Higgs boson particle. 

New interdisciplinary hub, Edinburgh Centre for Biomedical Physics, tackles health challenges.

The newly established Edinburgh Centre for Biomedical Physics will bring together researchers from physics, chemistry, biology, data science and medicine to tackle pressing challenges in human and animal health.

The Centre will focus on areas such as advanced medical imaging (including PET and machine-learning-enhanced image analysis), the physical and molecular mechanisms underlying diseases such as cancer, conditions like autism, and the physics of viruses and infection spread. By combining experimental, computational, and theoretical expertise, the Centre aims to address some of the most complex problems in modern biomedicine – problems that no single discipline can solve alone.

The Centre will act as a hub linking the School of Physics and Astronomy with clinical and research partners across the University, including the Little France campus, the Roslin Institute, and the Institute for Genetics and Cancer at the Western General. Everyone with an interest in physics-driven approaches to clinical problems is very welcome within the Centre going forward.

In addition to supporting collaborations and training, the Centre will host a seminar series across its main research themes and a yearly workshop for the wider research community. Longer-term plans include developing an MSc programme in Biomedical Physics and exploring opportunities for joint PhD training.

As the first centre of its kind in Scotland focused on the interface of physics, modelling and molecular-scale biomedical mechanisms, it will provide a unique environment for interdisciplinary discovery with long-term benefits for research, healthcare innovation and society.

Professor Jim Dunlop, former Head of School said:

The Edinburgh Centre for Biomedical Physics represents a very exciting step forward for our School and our partners across the University. By bringing together complementary expertise from the physical and life sciences, the Centre will enable new approaches to important questions in biomedical science. Our School can be genuinely proud of the key role that our physicists have played in shaping the interdisciplinary collaborations which underpin the Centre. This exciting initiative has the potential to redefine the future of this vital and rapidly evolving field.

Families enjoyed a night of spooky science at the Annual Higgs Halloween Lecture.

Families, students and members of the public gathered at the Anatomy Lecture Theatre on 30 October for this year’s Higgs Halloween Lecture — A Dangerous Shade of Green — an evening of spooky science, colour and curiosity.

Speaker Dr Drew Rosen from the School of Physics and Astronomy explored the fascinating history and science behind pigments and poisons, revealing how one particular shade of green concealed a toxic secret.

The interactive talk delved into how we see and measure colour, combining science and storytelling to uncover a spine-tingling side of discovery.

The evening was designed for family fun, with children —and adults — dressed in Halloween costumes. Prizes were awarded for the most creative outfits and the spookiest jokes.

The Higgs Halloween Lecture is an annual event bringing science to life for audiences of all ages — blending education, entertainment and a hint of fright.

Congratulations to Peter Black, who received a Technician Award for his contributions to advancing research and innovation.

In September 2025, colleagues celebrated the third annual University of Edinburgh Technician Awards. With over 100 nominations across five categories, the Awards highlighted the skill, creativity, and dedication that technicians bring to the University. 

Peter Black, Nuclear Physics Lab Manager in the School of Physics and Astronomy was joint winner of the Contribution to Research and Innovation award category, which recognises technical staff who have made significant contributions to advancing research and innovation within their field.

Peter was praised for his inventive design solutions, including leading the development of a new compact scattering chamber for silicon detector experiments. His ingenuity has advanced the School’s international research profile and inspired colleagues and students alike.

The winners and the shortlisted nominees were presented with certificates and vouchers at the award ceremony by Professor Kim Graham, Provost, and Dr Catherine Martin, Vice-Principal Corporate Services.

Researchers have unveiled a powerful new way to control ultra-thin magnetic materials which could pave the way for faster, greener technologies for computing and data storage.

Ultrathin magnets

Two-dimensional (2D) magnets are sheets of magnetic material only a few atoms thick. Because they are so thin, their magnetic behaviour can be tuned far more easily than in conventional bulk magnets. This makes them a hot candidate for spintronics devices, which use the spin of electrons instead of their charge to process and store information. Spintronic devices promise to be much faster and more energy-efficient than today’s electronics.

Ground breaking discovery

A team of researchers led by Dr Elton Santos from the School of Physics and Astronomy, showed that femtosecond laser pulses (that’s millionths of a billionth of a second) can flip the magnetisation of these materials at speeds far beyond traditional magnetic switching. Doing so with light rather than magnetic fields slashes the energy cost of each switching event and removes the need for mechanical components, allowing denser information storage with less wear and tear, significantly expanding their lifetime. The findings are featured on the front cover of Advanced Materials.

Challenges

However, this ultra-fast control comes with a challenge: heat. When such intense, ultrashort pulses hit a tiny magnetic layer, the material heats up almost instantly. If the heat can’t escape, it slows down or even disrupts the switching process. For real-world applications, controlling how heat flows away from these atom-thin layers is just as important as controlling their magnetism.

Substrate influence

To address this, the team tested three representative 2D magnets (semiconducting Cr₂Ge₂Te₆, insulating CrI₃ and metallic Fe₃GeTe₂) on a wide range of underlying substrates such as silicon dioxide, hexagonal boron nitride, graphene and other crystals. They discovered that simply choosing a different substrate changes how quickly the magnet heats and cools, and therefore how quickly it can be switched on and off by light. Substrates with higher thermal conductivity act like miniature heat sinks, letting the magnet cool down and recover its state much faster.

They also found that thinner magnetic layers reset their magnetisation more quickly than thicker ones, and that the timescales follow a clear trend linked to the substrate’s heat-handling properties. On top of the thermal effects, the researchers observed fleeting bursts of spin-polarized currents at the interface (a kind of ultrafast spin signal) that doesn’t appear in conventional thin films. These currents could be harnessed for new types of high-frequency spintronic circuits operating in the gigahertz range.

Implications

Together, these results give engineers a toolkit for designing devices where magnetism, heat and speed can be tuned on demand. In practical terms, that could mean much faster and more energy-efficient hard drives, memory chips and logic devices — all operating with light pulses instead of heavy electrical currents. It could also enable entirely new architectures for data-intensive tasks such as artificial intelligence, cloud computing and telecommunications, where today’s electronics face rising energy costs and heat bottlenecks.

By showing how to integrate ultrathin magnets with the right supporting materials, this research brings the dream of low-power, ultrafast spintronic technology a major step closer — and highlights the unique potential of 2D materials to go beyond the limits of today’s magnetic devices.

Astronomers have used observatories around the world to study asteroid 1998 KY26, revealing it to be almost three times smaller and spinning much faster than previously thought.

Asteroid 1998 KY26

An international team of researchers used observatories around the world to study asteroid 1998 KY26 to support the preparation of the future Hayabusa2 mission. Because the asteroid is very small and, hence, very faint, studying it required waiting for a close encounter with Earth and using large telescopes, like the European Southern Observatory's Very Large Telescope (ESO’s VLT) in Chile’s Atacama Desert. 

Researchers from the Institute for Astronomy were involved in determining the size of the asteroid using ESO’s VLT observations, models gathered from the international team, and by reprocessing archival radar data. The Edinburgh contribution was crucial because, while other techniques could constrain how fast the object rotates and what its composition is, adding the radar data allowed the team to determine the size with meter-level precision.

Hayabusa2 spacecraft mission

Asteroid 1998 KY26 is set to be the final target asteroid for the Japanese Aerospace eXploration Agency (JAXA)'s Hayabusa2 spacecraft.

In its original mission, Hayabusa2 explored the 900-metre-diameter asteroid 162173 Ryugu in 2018, returning asteroid samples to Earth in 2020.

With fuel remaining, the spacecraft was sent on an extended mission until 2031, when it’s set to encounter 1998 KY26 which measures just 11 metres in diameter - the first time a space mission encounters such a tiny asteroid.

Outcomes

With the ability to characterise such small objects, astronomers can identify further such objects in the future. The team believes this could have impact on future near-Earth asteroid exploration or even asteroid mining.

Researchers share insights that should help those who are particularly untidy.

Have you ever spent too much time searching for your lost keys? Retracing your steps from the start may seem like the obvious solution, but have you ever considered an alternative search strategy?

Recent insights reveal that taking a step back and starting afresh at random intervals, rather than sticking to a set routine, could be the trick to finding misplaced items more efficiently.

Search problems are ubiquitous in nature: from animals foraging for food to the search of biomolecules for targets inside living cells.  One effective search strategy is to reset the search every so often and start anew. The idea has proven useful in many different contexts, including optimizing the performance of computer algorithms, chemical reactions and biophysical processes.  In a nutshell, resetting stops the search from wandering off in the wrong direction.

Resetting has been of particular interest in the statistical physics community where it provides a paradigm of nonequilibrium dynamics: by continually restarting some complex process, the process is never allowed to equilibrate. A particularly appealing mathematical model is diffusion, perhaps the simplest and most common process in nature, with the addition of resetting.

Researchers Professor Martin Evans and Dr Somrita Ray (Elizabeth Gardner Fellow) wanted to investigate when resetting a diffusive search at random intervals (stochastic resetting) is advantageous compared to resetting at fixed intervals (sharp restart). They were able to prove mathematically and substantiate with computer simulations that stochastic resetting is the superior strategy when the distribution of the target of the search is broad. Moreover, they provided a formula determining the target distribution to which a resetting protocol is best suited.

To understand the target distribution, let’s return to the everyday example of searching for one's keys (the target). Usually when we go to retrieve our keys, they are not there and are instead located at some random distance from where they should be, how far depending on how untidy we are.  Thus being untidy implies a broad target distribution.

We conclude that for those who tend to be on the untidy side, applying this random reset method can drastically improve your chances of locating lost items!

The School has announced the names of the research students who have produced the best PhD thesis.

The School awards annual prizes to postgraduate research students who have produced the best PhD thesis in each of the research areas. The prizes come with a cash award of £1000. The prizes are awarded in 2025 for research work successfully defended in 2024.

The winners are:

Many congratulations to all recipients.

Professor Andrzej Szelc has been elected as spokesperson for an international collaboration focused in neutrino detection.

The experiment, known as the Short-Baseline Near Detector (SBND), records over a million neutrino interactions per year and is essential for studying neutrino oscillations. It will preform precise measurements of neutrino interactions and search for new particles that might be hidden within the neutrino  beam. Located at Fermilab, America's particle physics and accelerator laboratory, the experiment started collecting data in December last year and has already acquired the largest sample of neutrino interactions on argon in the world.

Fermilab is home to a number of particle physics experiments, aimed at understanding the smallest building blocks of matter, and therefore helping answer fundamental questions on what are we made of, how the universe began, and the nature of dark matter and dark energy.

The SBND experiment is a collaboration of around 220 physicists from 41 institutions from the US, UK, Brazil, Spain and Switzerland, and will continue acquiring data at least until 2027, when the accelerator complex will shut down for two years to install an upgrade needed for the future DUNE experiment. Professor Andrzej Szelc will lead the SBND as its spokesperson for a two-year term.

He is the first spokesperson elected from outside the USA.

Professor Andrzej Szelc said: 

SBND is an amazing detector that will acquire an unprecedented amount of data and, thanks to the diligent work of many scientists around the World, will be able to extract physics measurement with fantastic precision. It is also a very fun collaboration to work in, with many great contributions from early career researchers:  students, post-docs – several of them from Edinburgh – that make this an excellent place to work in. It is a great honour to be elected as the SBND spokesperson and help lead the experiment in this extremely exciting period of data taking and first results. 

Professor Andrzej Szelc joined the University of Edinburgh in December 2020. Most of his career has been spent working on developing liquid argon detectors to search for rare processes. He has been part of the Fermilab liquid-argon neutrino programme since 2011 and has worked on measurements of electron-neutrino cross sections, searches for beyond the standard model particles, as well as developing applications for scintillation light in these detectors.