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Freedom in the Equation exhibition opens at Harvard Science Centre

A new exhibition dedicated to Ukrainian scientists has opened at Harvard Science Centre in the Cambridge, Massachusetts, in the US.

The exhibition – Freedom in the Equation – shares the stories of 10 scientists to highlight Ukraine’s lost scientific potential due to Russia’s aggression towards the country while also shedding light on the contributions of Ukrainian scientists.

Among them are physicists Vasyl Kladko and Lev Shubnikov. Kladko worked on semiconductor physics and was deputy director of the Institute of Semiconductor Physics in Kyiv. He was killed in 2022 at the age of 65 as he tried to help his family flee Russia’s invasion.

Shubnikov, meanwhile, established a cryogenic lab at the Ukrainian Institute of Physics and Technology in Kharkiv (now known as the Kharkiv Institute of Physics and Technology) in the early 1930s. In 1937, Shubnikov was arrested during Stalin’s regime and accused of espionage and was executed shortly after.

The scientists were selected by Oleksii Boldyrev, a molecular biologist and founder of the online platform myscience.ua, together with Krystyna Semeryn, a literary scholar and publicist.

The portraits were created by Niklas Elemehed, who is the official artist of the Nobel prize, with the text compiled by Olesia Pavlyshyn, editor-in-chief at the Ukrainian popular-science outlet Kunsht.

The exhibition, which is part of the Science at Risk project, runs until 10 March. “Today, I witness scientists being killed, and preserving their names has become a continuation of my work in historical research and a continuation of resistance against violence toward Ukrainian science,” says Boldyrev.

Schrödinger’s cat states appear in the nuclear spin state of antimony

Physicists at the University of New South Wales (UNSW) are the first to succeed in creating and manipulating quantum superpositions of a single, large nuclear spin. The superposition involves spin states that are very far apart and are therefore the superposition is considered a Schrödinger’s cat state. The work could be important for applications in quantum information processing and quantum error correction.

It was Erwin Schrödinger who, in 1935, devised his famous thought experiment involving a cat that could, worryingly, be both dead and alive at the same time. In his gedanken experiment, the decay of a radioactive atom triggers a mechanism (the breaking of a vial containing a poisonous gas) that kills the cat. However, since the decay of the radioactive atom is a quantum phenomenon, the atom is in a superposition of being decayed and not decayed. If the cat and poison are hidden in a box, we do not know if the cat is alive or dead. Instead, the state of the feline is a superposition of dead and alive – known as a Schrödinger’s cat state – until we open the box.

Schrödinger’s cat state (or just cat state) is now used to refer a superposition of two very different states of a quantum system. Creating cat states in the lab is no easy task, but researchers have managed to do this in recent years using the quantum superposition of coherent states of a laser field with different amplitudes, or phases, of the field. They have also created cat states using a trapped ion (with the vibrational state of the ion in the trap playing the role of the cat) and coherent microwave fields confined to superconducting boxes combined with Rydberg atoms and superconducting quantum bits (qubits).

Antimony atom cat

The cat state in the UNSW study is an atom of antimony, which is a heavy atom with a large nuclear spin. The high spin value implies that, instead of just pointing up and down (that is, in one of two directions), the nuclear spin of antimony can be in spin states corresponding to eight different directions. This makes it a high-dimensional quantum system that is valuable for quantum information processing and for encoding error-correctable logical qubits. The atom was embedded in a silicon quantum chip that allows for readout and control of the nuclear spin state.

Normally, a qubit, is described by just two quantum states, explains Xi Yu, who is lead author of a paper describing the study. For example, an atom with its spin pointing down can be labelled as the “0” state and the spin pointing up, the “1” state. The problem with such a system is that information contained in these states is fragile and can be easily lost when a 0 switches to a 1, or vice versa. The probability of this logical error occurring is reduced by creating a qubit using a system like the antinomy atom. With its eight different spin directions, a single error is not enough to erase the quantum information – there are still seven quantum states left, and it would take seven consecutive errors to turn the 0 into a 1.

More room for error

The information is still encoded in binary code (0 and 1), but there is more room for error between the logical codes, says team leader Andrea Morello. “If an error occurs, we detect it straight away, and we can correct it before further errors accumulate.”

The researchers say they were not initially looking to make and manipulate cat states but started with a project on high-spin nuclei for reasons unrelated to quantum information. They were in fact interested in observing quantum chaos in a single nuclear spin, which had been an experimental “holy grail” for a very long time, says Morello. “Once we began working with this system, we first got derailed by the serendipitous discovery of nuclear electric resonance, he remembers “We then became aware of some new theoretical ideas for the use of high-spin systems in quantum information and quantum error correcting codes.

“We therefore veered towards that research direction, and this is our first big result in that context,” he tells Physics World.

Scalable technology

The main challenge the team had to overcome in their study was to set up seven “clocks” that had to be precisely synchronized, so they could keep track of the quantum state of the eight-level system. Until quite recently, this would have involved cumbersome programming of waveform generators, explains Morello. “The advent of FPGA [field-programmable gate array] generators, tailored for quantum applications, has made this research much easier to conduct now.”

Schrödinger’s cat makes a better qubit in critical regime

Conceptual illustration showing interference fringes between a "dead" state (represented by a cat lying down) and a "live" state (represented by a cat walking away)

While there have already been a few examples of such physical platforms in which quantum information can be encoded in a (Hilbert) space of dimension larger than two – for example, microwave cavities or trapped ions – these were relatively large in size: bulk microwave cavities are typically the size of matchbox, he says. “Here, we have reconstructed many of the properties of other high-dimensional systems, but within an atomic-scale object – a nuclear spin. It is very exciting, and quite plausible, to imagine a quantum processor in silicon, containing millions of such Schrödinger cat states.”

The fact that the cat is hosted in a silicon chip means that this technology could be scaled up in the long-term using methods similar to those already employed in the computer chip industry today, he adds.

Looking ahead, the UNSW team now plans to demonstrate quantum error correction in its antimony system. “Beyond that, we are working to integrate the antimony atoms with lithographic quantum dots, to facilitate the scalability of the system and perform quantum logic operations between cat-encoded qubits,” reveals Morello.

The present study is detailed in Nature Physics.

Quantum superstars gather in Paris for the IYQ 2025 opening ceremony

The United Nations Educational, Scientific and Cultural Organization (UNESCO) has declared 2025 the International Year of Quantum Science and Technology – or IYQ.

UNESCO kicked-off IYQ on 4–5 February at a gala opening ceremony in Paris. Physics World’s Matin Durrani was there, and he shares his highlights from the event in this episode of the Physics World Weekly podcast.

No fewer than four physics Nobel laureates took part in the ceremony alongside representatives from governments and industry. While some speakers celebrated the current renaissance in quantum research and the burgeoning quantum-technology sector, others called on the international community to ensure that people in all nations benefit from a potential quantum revolution – not just people in wealthier countries. The dangers of promising too much from quantum computers and other technologies, was also discussed – as Durrani explains.

This article forms part of Physics World‘s contribution to the 2025 International Year of Quantum Science and Technology (IYQ), which aims to raise global awareness of quantum physics and its applications.

Stayed tuned to Physics World and our international partners throughout the next 12 months for more coverage of the IYQ.

Find out more on our quantum channel.

US science in chaos as impact of Trump’s executive orders sinks in

Scientists across the US have been left reeling after a spate of executive orders from US President Donald Trump has led to research funding being slashed, staff being told to quit and key programmes being withdrawn. In response to the orders, government departments and external organizations have axed diversity, equity and inclusion (DEI) programmes, scrubbed mentions of climate change from websites, and paused research grants pending tests for compliance with the new administration’s goals.

Since taking up office on 20 January, Trump has signed dozens of executive orders. One ordered the closure of the US Agency for International Development, which has supported medical and other missions worldwide for more than six decades. The administration said it was withdrawing almost all of the agency’s funds and wanted to sack its entire workforce. A federal judge has temporarily blocked the plans, saying they may violate the US’s constitution, which reserves decisions on funding to Congress.

Individual science agencies are under threat too. Politico reported that the Trump administration has asked the National Science Foundation (NSF), which funds much US basic and applied research, to lay off between a quarter and a half of its staff in the next two months. Another report suggests there are plans to cut the agency’s annual budget from roughly $9bn to $3bn. Meanwhile, former officials of the National Oceanic and Atmospheric Administration (NOAA) told CBS News that half its staff could be sacked and its budget slashed by 30%.

Even before they had learnt of plans to cut its staff and budget, officials at the NSF were starting to examine details of thousands of grants it had awarded for references to DEI, climate change and other topics that Trump does not like. The swiftness of the announcements has caused chaos, with recipients of grants suddenly finding themselves unable to access the NSF’s award cash management service, which holds grantees’ funds, including their salaries.

NSF bosses have taken some steps to reassure grantees. “Our top priority is resuming our funding actions and services to the research community and our stakeholders,” NSF spokesperson Mike England told Physics World in late January. In what is a highly fluid situation, there was some respite on 2 February when the NSF announced that access had been restored with the system able to accept payment requests.

“Un-American” actions

Trump’s anti-DEI orders have caused shockwaves throughout US science. According to 404 Media, NASA staff were told on 22 January to “drop everything” to remove mentions of DEI, Indigenous people, environmental justice and women in leadership, from public websites. Another victim has been NASA’s Here to Observe programme, which links undergraduates from under-represented groups with scientists who oversee NASA’s missions. Science reported that contracts for half the scientists involved in the programme had been cancelled by the end of January.

It is still unclear, however, what impact the Trump administration’s DEI rules will have on the make-up of NASA’s astronaut corps. Since choosing its first female astronaut in 1978, NASA has sought to make the corps more representative of US demographics. How exactly the agency should move forward will fall to Jared Isaacman, the space entrepreneur and commercial astronaut who has been nominated as NASA’s next administrator.

Anti-DEI initiatives have hit individual research labs too. Physics World understands that Fermilab – the US’s premier particle-physics lab – suspended its DEI office and its women in engineering group in January. Meanwhile, the Fermilab LBGTQ+ group, called Spectrum, was ordered to cease all activities and its mailing list deleted. Even the rainbow “Pride” flag was removed from the lab’s iconic Wilson Hall.

Some US learned societies, despite being formally unaffiliated with the government, have also responded to pressure from the new administration. The American Geophysical Union (AGU) removed the word “diversity” from its diversity and inclusion page, although it backtracked after criticism of the move.

There was also some confusion that the American Chemical Society had removed its webpage on diversity and inclusion, but they had in fact published a new page and failed to put a redirect in place. “Inclusion and Belonging is a core value of the American Chemical Society, and we remain committed to creating environments where people from diverse backgrounds, cultures, perspectives and experiences thrive,” a spokesperson told Physics World. “We know the broken link caused confusion and some alarm, and we apologize.”

For the time being, the American Physical Society’s page on inclusion remains live, as does that of the American Institute of Physics.

Dismantling all federal DEI programmes and related activities will damage lives and careers of millions of American women and men
Neal Lane, Rice University

Such a response – which some opponents denounce as going beyond what is legally required for fear of repercussions if no action is taken – has left it up to individual leaders to underline the importance of diversity in science. Neal Lane, a former science adviser to President Clinton, told Physics World that “dismantling all federal DEI programmes and related activities will damage lives and careers of millions of American women and men, including scientists, engineers, technical workers – essentially everyone who contributes to advancing America’s global leadership in science and technology”.

Lane, who is now a science and technology policy fellow at Rice University in Texas, think that the new administration’s anti-DEI actions “will weaken the US” and believes they should be considered “un-American”. “The purpose of DEI policies programmes and activities is to ensure all Americans have the opportunity to participate and the country is able to benefit from their participation,” he says.

One senior physicist at a US university, who wishes to remain anonymous, told Physics World that those behind the executive orders are relying on institutions and individuals to “comply in advance” with what they perceive to be the spirit of the orders. “They are relying on people to ignore the fine print, which says that executive orders can’t and don’t overwrite existing law. But it is up to scientists to do the reading — and to follow our consciences. More than universities are on the line: the lives of our students and colleagues are on the line.”

Education turmoil

Another target of the Trump administration is the US Department of Education, which was set up in 1978 to oversee everything from pre-school to postgraduate education. It has already put dozens of its civil servants on leave, ostensibly because their work involves DEI issues. Meanwhile, the withholding of funds has led to the cancellation of scientific meetings, mostly focusing on medicine and life sciences, that were scheduled in the US for late January and early February.

Colleges and universities in the US have also reacted to Trump’s anti-DEI executive order. Academic divisions at Harvard University and the Massachusetts Institute of Technology, for example, have already indicated that they will no longer require applicants for jobs to indicate how they plan to advance the goals of DEI. Northeastern University in Boston has removed the words “diversity” and “inclusion” from a section of its website.

Not all academic organizations have fallen into line, however. Danielle Holly, president of the women-only Mount Holyoke College in South Hadley, Massachusetts, says it will forgo contracts with the federal government if they required abolishing DEI. “We obviously can’t enter into contracts with people who don’t allow DEI work,” she told the Boston Globe. “So for us, that wouldn’t be an option.”

Climate concerns

For an administration that doubts the reality of climate change and opposes anti-pollution laws, the Environmental Protection Agency (EPA) is under fire too. Trump administration representatives were taking action even before the Senate approved Lee Zeldin, a former Republican Congressman from New York who has criticized much environmental legislation, as EPA Administrator. They removed all outside advisers on the EPA’s scientific advisory board and its clean air scientific advisory committee – purportedly to “depoliticize” the boards.

Once the Senate approved Zeldin on 29 January, the EPA sent an e-mail warning more than 1000 probationary employees who had spent less than a year in the agency that their roles could be “terminated” immediately. Then, according to the New York Times, the agency developed plans to demote longer-term employees who have overseen research, enforcement of anti-pollution laws, and clean-ups of hazardous waste. According to Inside Climate News, staff also found their individual pronouns scrubbed from their e-mails and websites without their permission – the result of an order to remove “gender ideology extremism”.

Critics have also questioned the nomination of Neil Jacobs to lead the NOAA. He was its acting head during Trump’s first term in office, serving during the 2019 “Sharpiegate” affair when Trump used a Sharpie pen to alter a NOAA weather map to indicate that Hurricane Dorian would affect Alabama. While conceding Jacobs’s experience and credentials, Rachel Cleetus of the Union of Concerned Scientists asserts that Jacobs is “unfit to lead” given that he “fail[ed] to uphold scientific integrity at the agency”.

Spending cuts

Another concern for scientists is the quasi-official team led by “special government employee” and SpaceX founder Elon Musk. The administration has charged Musk and his so-called “department of government efficiency”, or DOGE, to identify significant cuts to government spending. Though some of DOGE’s activities have been blocked by US courts, agencies have nevertheless been left scrambling for ways to reduce day-to-day costs.

The National Institutes of Health (NIH), for example, has said it will significantly reduce its funding for “indirect” costs of research projects it supported – the overheads that, for example, cover the cost of maintaining laboratories, administering grants, and paying staff salaries. Under the plans, indirect cost reimbursement for federally funded research would be capped at 15%, a drastic cut from its usual range.

NIH personnel have tried to put a positive gloss on its actions. “The United States should have the best medical research in the world,” a statement from NIH declared. “It is accordingly vital to ensure that as many funds as possible go towards direct scientific research costs rather than administrative overhead.”

Just because Elon Musk doesn’t understand indirect costs doesn’t mean Americans should have to pay the price with their lives
US senator Patty Murray

Opponents of the Trump administration, however, are unconvinced. They argue that the measure will imperil critical clinical research because many academic recipients of NIH funds did not have the endowments to compensate for the losses. “Just because Elon Musk doesn’t understand indirect costs doesn’t mean Americans should have to pay the price with their lives,” says US senator Patty Murray, a Democrat from Washington state.

Slashing universities’ share of grants to below 15%, could, however, force institutions to make up the lost income by raising tuition fees, which could “go through the roof”, according to the anonymous senior physicist contacted by Physics World. “Far from being a populist policy, these cuts to overheads are an attack on the subsidies that make university education possible for students from a range of socioeconomic backgrounds. The alternative is to essentially shut down the university research apparatus, which would in many ways be the death of American scientific leadership and innovation.”

Musk and colleagues have also gained unprecedented access to government websites related to civil servants and the country’s entire payments system. That access has drawn criticism from several commentators who note that, since Musk is a recipient of significant government support through his SpaceX company, he could use the information for his own advantage.

“Musk has access to all the data on federal research grantees and contractors: social security numbers, tax returns, tax payments, tax rebates, grant disbursements and more,” wrote physicist Michael Lubell from City College of New York. “Anyone who depends on the federal government and doesn’t toe the line might become a target. This is right out of (Hungarian prime minister) Viktor Orbán’s playbook.”

A new ‘dark ages’

As for the long-term impact of these changes, James Gates – a theoretical physicist at the University of Maryland and a past president of the US National Society of Black Physicists – is blunt. “My country is in for a 50-year period of a new dark ages,” he told an audience at the Royal College of Art in London, UK, on 7 February.

My country is in for a 50-year period of a new dark ages
James Gates, University of Maryland

Speaking at an event sponsored by the college’s association for Black students – RCA BLK – and supported by the UK’s organization for Black physicists, the Blackett Lab Family, he pointed out that the US has been through such periods before. As examples, Gates cited the 1950s “Red Scare” and the period after 1876 when the federal government abandoned efforts to enforce the civil rights of Black Americans in southern states and elsewhere.

However, he is not entirely pessimistic. “Nothing is permanent in human behaviour. The question is the timescale,” Gates said. “There will be another dawn, because that’s part of the human spirit.”

With additional reporting by Margaret Harris, online editor of Physics World, in London and Michael Banks, news editor of Physics World

Bacterial ‘cables’ form a living gel in mucus

Bacterial cells in solutions of polymers such as mucus grow into long cable-like structures that buckle and twist on each other, forming a “living gel” made of intertwined cells. This behaviour is very different from what happens in polymer-free liquids, and researchers at the California Institute of Technology (Caltech) and Princeton University, both in the US, say that understanding it could lead to new treatments for bacterial infections in patients with cystic fibrosis. It could also help scientists understand how cells organize themselves into polymer-secreting conglomerations of bacteria called biofilms that can foul medical and industrial equipment.

Interactions between bacteria and polymers are ubiquitous in nature. For example, many bacteria live as multicellular colonies in polymeric fluids, including host-secreted mucus, exopolymers in the ocean and the extracellular polymeric substance that encapsulates biofilms. Often, these growing colonies can become infectious, including in cystic fibrosis patients, whose mucus is more concentrated than it is in healthy individuals.

Laboratory studies of bacteria, however, typically focus on cells in polymer-free fluids, explains study leader Sujit Datta, a biophysicist and bioengineer at Caltech. “We wondered whether interactions with extracellular polymers influence proliferating bacterial colonies,” says Datta, “and if so, how?”

Watching bacteria grow in mucus

In their work, which is detailed in Science Advances, the Caltech/Princeton team used a confocal microscope to monitor how different species of bacteria grew in purified samples of mucus. The samples, Dutta explains, were provided by colleagues at the Massachusetts Institute of Technology and the Albert Einstein College of Medicine.

Normally, when bacterial cells divide, the resulting “daughter” cells diffuse away from each other. However, in polymeric mucus solutions, Datta and colleagues observed that the cells instead remained stuck together and began to form long cable-like structures. These cables can contain thousands of cells, and eventually they start bending and folding on top of each other to form an entangled network.

“We found that we could quantitively predict the conditions under which such cables form using concepts from soft-matter physics typically employed to describe non-living gels,” Datta says.

Support for bacterial colonies

The team’s work reveals that polymers, far from being a passive medium, play a pivotal role in supporting bacterial life by shaping how cells grow in colonies. The form of these colonies – their morphology – is known to influence cell-cell interactions and is important for maintaining their genetic diversity. It also helps determine how resilient a colony is to external stressors.

“By revealing this previously-unknown morphology of bacterial colonies in concentrated mucus, our finding could help inform ways to treat bacterial infections in patients with cystic fibrosis, in which the mucus that lines the lungs and gut becomes more concentrated, often causing the bacterial infections that take hold in that mucus to become life-threatening,” Datta tells Physics World.

Friend or foe?

As for why cable formation is important, Datta explains that there are two schools of thought. The first is that by forming large cables, bacteria may become more resilient against the body’s immune system, making them more infectious. The other possibility is that the reverse is true – that cable formation could in fact leave bacteria more exposed to the host’s defence mechanisms. These include “mucociliary clearance”, which is the process by which tiny hairs on the surface of the lungs constantly sweep up mucus and propel it upwards.

“Could it be that when bacteria are all clumped together in these cables, it is actually easier to get rid of them by expelling them out of the body?” Dutta asks.

Investigating these hypotheses is an avenue for future research, he adds. “Ours is a fundamental discovery on how bacteria grow in complex environments, more akin to their natural habitats,” Datta says. “We also expect it will motivate further work exploring how cable formation influences the ways in which bacteria interact with hosts, phages, nutrients and antibiotics.”

Sarah Sheldon: how a multidisciplinary mindset can turn quantum utility into quantum advantage

IBM is on a mission to transform quantum computers from applied research endeavour to mainstream commercial opportunity. It wants to go beyond initial demonstrations of “quantum utility”, where these devices outperform classical computers only in a few niche applications, and reach the new frontier of “quantum advantage”. That’ll be where quantum computers routinely deliver significant, practical benefits beyond approximate classical computing methods, calculating solutions that are cheaper, faster and more accurate.

Unlike classical computers, which rely on the binary bits that can be either 0 or 1, quantum computers exploit quantum binary bits (qubits), but as a superposition of 0 and 1 states. This superposition, coupled with quantum entanglement (a correlation of two qubits), enables quantum computers to perform some types of calculation significantly faster than classical machines, such as problems in quantum chemistry and molecular reaction kinetics.

In the vanguard of IBM’s quantum R&D effort is Sarah Sheldon, a principal research scientist and senior manager of quantum theory and capabilities at the IBM Thomas J Watson Research Center in Yorktown Heights, New York. After a double-major undergraduate degree in physics and nuclear science and engineering at Massachusetts Institute of Technology (MIT), Sheldon received her PhD from MIT in 2013 – though she did much of her graduate research in nuclear science and engineering as a visiting scholar at the Institute for Quantum Computing (IQC) at the University of Waterloo, Canada.

At IQC, Sheldon was part of a group studying quantum control techniques, manipulating the spin states of nuclei in nuclear-magnetic-resonance (NMR) experiments. “Although we were using different systems to today’s leading quantum platforms, we were applying a lot of the same kinds of control techniques now widely deployed across the quantum tech sector,” Sheldon explains.

“Upon completion of my PhD, I opted instinctively for a move into industry, seeking to apply all that learning in quantum physics into immediate and practical engineering contributions,” she says. “IBM, as one of only a few industry players back then with an experimental group in quantum computing, was the logical next step.”

Physics insights, engineering solutions

Sheldon currently heads a cross-disciplinary team of scientists and engineers developing techniques for handling noise and optimizing performance in novel experimental demonstrations of quantum computers. It’s ambitious work that ties together diverse lines of enquiry spanning everything from quantum theory and algorithm development to error mitigation, error correction and techniques for characterizing quantum devices.

We’re investigating how to extract the optimum performance from current machines online today as well as from future generations of quantum computers.
Sarah Sheldon, IBM

“From algorithms to applications,” says Sheldon, “we’re investigating what can we do with quantum computers: how to extract the optimum performance from current machines online today as well as from future generations of quantum computers – say, five or 10 years down the line.”

A core priority for Sheldon and colleagues is how to manage the environmental noise that plagues current quantum computing systems. Qubits are all too easily disturbed, for example, by their interactions with environmental fluctuations in temperature, electric and magnetic fields, vibrations, stray radiation and even interference between neighbouring qubits.

The ideal solution – a strategy called error correction – involves storing the same information across multiple qubits, such that errors are detected and corrected when one or more of the qubits are impacted by noise. But the problem with these so-called “fault-tolerant” quantum computers is they need millions of qubits, which is impossible to implement in today’s small-scale quantum architectures. (For context, IBM’s latest Quantum Development Roadmap outlines a practical path to error-corrected quantum computers by 2029.)

“Ultimately,” Sheldon notes, “we’re working towards large-scale error-corrected systems, though for now we’re exploiting near-term techniques like error mitigation and other ways of managing noise in these systems.” In practical terms, this means implementing quantum architectures without increasing the number of qubits – essentially, integrating them with classical computers to reduce noise through increasing samples on the quantum computer combined with classical processing.

Strength in diversity

For Sheldon, one big selling point of the quantum tech industry is the opportunity to collaborate with people from a wide range of disciplines. “My team covers a broad-scope R&D canvas,” she says. There are mathematicians and computer scientists, for example, working on complexity theory and novel algorithm development; physicists specializing in quantum simulation and incorporating error suppression techniques; as well as quantum chemists working on simulations of molecular systems.

“Quantum is so interdisciplinary – you are constantly learning something new from your co-workers,” she adds. “I started out specializing in quantum control techniques, before moving onto experimental demonstrations of larger multiqubit systems while working ever more closely with theorists.”

A corridor in IBM's quantum lab — **Computing reimagined** Quantum scientists and engineers at the IBM Thomas J Watson Research Center are working to deliver IBM’s Quantum Development Roadmap and a practical path to error-corrected quantum computers by 2029. (Courtesy: Connie Zhou for IBM)

External research collaborations are also mandatory for Sheldon and her colleagues. Front-and-centre is the IBM Quantum Network, which provides engagement opportunities with more than 250 organizations across the “quantum ecosystem”. These range from top-tier labs – such as CERN, the University of Tokyo and the UK’s National Quantum Computing Centre – to quantum technology start-ups like Q-CTRL and Algorithmiq. It also encompasses established industry players aiming to be early-adopting end-users of quantum technologies (among them Bosch, Boeing and HSBC).

“There’s a lot of innovation happening across the quantum community,” says Sheldon, “so external partnerships are incredibly important for IBM’s quantum R&D programme. While we have a deep and diverse skill set in-house, we can’t be the domain experts across every potential use-case for quantum computing.”

Opportunity knocks

Notwithstanding the pace of innovation, there are troubling clouds on the horizon. In particular, there is a shortage of skilled workers in the quantum workforce, with established technology companies and start-ups alike desperate to attract more physical scientists and engineers. The task is to fill not only specialist roles – be it error-correction scientists or quantum-algorithm developers – but more general positions such as test and measurement engineers, data scientists, cryogenic technicians and circuit designers.

Yet Sheldon remains upbeat about addressing the skills gap. “There are just so many opportunities in the quantum sector,” she notes. “The field has changed beyond all recognition since I finished my PhD.” Perhaps the biggest shift has been the dramatic growth of industry engagement and, with it, all sorts of attractive career pathways for graduate scientists and engineers. Those range from firms developing quantum software or hardware to the end-users of quantum technologies in sectors such as pharmaceuticals, finance or healthcare.

“As for the scientific community,” argues Sheldon, “we’re also seeing the outline take shape for a new class of quantum computational scientist. Make no mistake, students able to integrate quantum computing capabilities into their research projects will be at the leading edge of their fields in the coming decades.”

Ultimately, Sheldon concludes, early-career scientists shouldn’t necessarily over-think things regarding that near-term professional pathway. “Keep it simple and work with people you like on projects that are going to interest you – whether quantum or otherwise.”

Stayed tuned to Physics World and our international partners throughout the year for more coverage of the IYQ.

Find out more on our quantum channel.

Nanoparticles demonstrate new and unexpected mechanism of coronavirus disinfection

The COVID-19 pandemic provided a driving force for researchers to seek out new disinfection methods that could tackle future viral outbreaks. One promising approach relies on the use of nanoparticles, with several metal and metal oxide nanoparticles showing anti-viral activity against SARS-CoV-2, the virus that causes COVID-19. With this in mind, researchers from Sweden and Estonia investigated the effect of such nanoparticles on two different virus types.

Aiming to elucidate the nanoparticles’ mode of action, they discovered a previously unknown antiviral mechanism, reporting their findings in Nanoscale.

The researchers – from the Swedish University of Agricultural Sciences (SLU) and the University of Tartu – examined triethanolamine terminated titania (TATT) nanoparticles, spherical 3.5-nm diameter titanium dioxide (titania) particles that are expected to interact strongly with viral surface proteins.

They tested the antiviral activity of the TATT nanoparticles against two types of virus: swine transmissible gastroenteritis virus (TGEV) – an enveloped coronavirus that’s surrounded by a phospholipid membrane and transmembrane proteins; and the non-enveloped encephalomyocarditis virus (EMCV), which does not have a phospholipid membrane. SARS-CoV-2 has a similar structure to TGEV: an enveloped virus with an outer lipid membrane and three proteins forming the surface.

“We collaborated with the University of Tartu in studies of antiviral materials,” explains lead author Vadim Kessler from SLU. “They had found strong activity from cerium dioxide nanoparticles, which acted as oxidants for membrane destruction. In our own studies, we saw that TATT formed appreciably stable complexes with viral proteins, so we could expect potentially much higher activity at lower concentration.”

In this latest investigation, the team aimed to determine whether one of these potential mechanisms – blocking of surface proteins, or membrane disruption via oxidation by nanoparticle-generated reactive oxygen species – is the likely cause of TATT’s antiviral activity. The first of these effects usually occurs at low (nanomolar to micromolar) nanoparticle concentrations, the latter at higher (millimolar) concentrations.

Mode of action

To assess the nanoparticle’s antiviral activity, the researchers exposed viral suspensions to colloidal TATT solutions for 1 h, at room temperature and in the dark (without UV illumination). For comparison, they repeated the process with silicotungstate polyoxometalate (POM) nanoparticles, which are not able to bind strongly to cell membranes.

The nanoparticle-exposed viruses were then used to infect cells and the resulting cell viability served as a measure of the virus infectivity. The team note that the nanoparticles alone showed no cytotoxicity against the host cells.

Measuring viral infectivity after nanoparticle exposure revealed that POM nanoparticles did not exhibit antiviral effects on either virus, even at relatively high concentrations of 1.25 mM. TATT nanoparticles, on the other hand, showed significant antiviral activity against the enveloped TGEV virus at concentrations starting from 0.125 mM, but did not affect the non-enveloped EMCV virus.

Based on previous evidence that TATT nanoparticles interact strongly with proteins in darkness, the researchers expected to see antiviral activity at a nanomolar level. But the finding that TATT activity only occurred at millimolar concentrations, and only affected the enveloped virus, suggests that the antiviral effect is not due to blocking of surface proteins. And as titania is not oxidative in darkness, the team propose that the antiviral effect is actually due to direct complexation of nanoparticles with membrane phospholipids – a mode of antiviral action not previously considered.

“Typical nanoparticle concentrations required for effects on membrane proteins correspond to the protein content on the virus surface. With a 1:1 complex, we would need maximum nanomolar concentrations,” Kessler explains. “We saw an effect at about 1 mM/l, which is far higher. This was the indication for us that the effect was on the whole of membrane.”

Verifying the membrane effect

To corroborate their hypothesis, the researchers examined the leakage of dye-labelled RNA from the TGEV coronavirus after 1 h exposure to nanoparticles. The fluorescence signal from the dye showed that TATT-treated TGEV released significantly more RNA than non-exposed virus, attributed to the nanoparticles disrupting the virus’s phospholipid membrane.

Finally, the team studied the interactions between TATT nanoparticles and two model phospholipid compounds. Both molecules formed strong complexes with TATT nanoparticles, while their interaction with POM nanoparticles was weak. This additional verification led the researchers to conclude that the antiviral effect of TATT in dark conditions is due to direct membrane disruption via complexation of titania nanoparticles with phospholipids.

“To the best of our knowledge, [this] proves a new pathway for metal oxide nanoparticles antiviral action,” they write.

Importantly, the nanoparticles are non-toxic, and work at room temperature without requiring UV illumination – enabling simple and low-cost disinfection methods. “While it was known that disinfection with titania could work in UV light, we showed that no special technical measures are necessary,” says Kessler.

Kessler suggests that the nanoparticles could be used to coat surfaces to destroy enveloped viruses, or in cost-effective filters to decontaminate air or water. “[It should be] possible to easily create antiviral surfaces that don’t require any UV activation just by spraying them with a solution of TATT, or possibly other oxide nanoparticles with an affinity to phosphate, including iron and aluminium oxides in particular,” he tells Physics World.

Organic photovoltaic solar cells could withstand harsh space environments

Carbon-based organic photovoltaics (OPVs) may be much better than previously thought at withstanding the high-energy radiation and sub-atomic particle bombardments of space environments. This finding, by researchers at the University of Michigan in the US, challenges a long-standing belief that OPV devices systematically degrade under conditions such as those encountered by spacecraft in low-Earth orbit. If verified in real-world tests, the finding suggests that OPVs could one day rival traditional thin-film photovoltaic technologies based on rigid semiconductors such as gallium arsenide.

Lightweight, robust, radiation-resilient photovoltaics are critical technologies for many aerospace applications. OPV cells are particularly attractive for this sector because they are ultra-lightweight, thermally stable and highly flexible. This last property allows them to be integrated onto curved surfaces as well as flat ones.

Today’s single-junction OPV devices also have a further advantage. Thanks to power conversion efficiencies (PCEs) that now exceed 20%, their specific power – that is, the power generated per weight – can be up to 40 W/g. This is significantly higher than traditional photovoltaic technologies, including those based on silicon (1 W/g) and gallium arsenide (3 W/g) on flexible substrates. Devices with such a large specific power could provide energy for small spacecraft heading into low-Earth orbit and beyond.

Until now, however, scientists believed that these materials had a fatal flaw for space applications: they weren’t robust to irradiation by the energetic particles (predominantly fluxes of electrons and protons) that spacecraft routinely encounter.

Testing two typical OPV materials

In the new work, researchers led by electrical and computer engineer Yongxi Li and physicist Stephen Forrest analysed how two typical OPV materials behave when exposed to proton particles with differing energies. They did this by characterizing their optoelectronic properties before and after irradiation exposure. The first materials were made up of small molecules (DBP, DTDCPB and C₇₀) that had been grown using a technique called vacuum thermal evaporation (VTE). The second group consisted of solution-processed small molecules and polymers (PCE-10, PM6, BT-CIC and Y6).

The team’s measurements show that the OPVs grown by VTE retained their initial PV efficiency under radiation fluxes of up to 10¹² cm⁻². In contrast, polymer-based OPVs lose 50% of their original efficiency under the same conditions. This, say the researchers, is because proton irradiation breaks carbon-hydrogen bonds in the polymers’ molecular alkyl side chains. This leads to polymer cross-linking and the generation of charge traps that imprison electrons and prevent them from generating useful current.

The good news, Forrest says, is that many of these defects can be mended by thermally annealing the materials at temperatures of 45 °C or less. After such an annealing, the cell’s PCE returns to nearly 90% of its value before irradiation. This means that Sun-facing solar cells made of these materials could essentially “self-heal”, though Forrest acknowledges that whether this actually happens in deep space is a question that requires further investigation. “It may be more straightforward to design the material so that the electron traps never appear in the first place or by filling them with other atoms, so eliminating this problem,” he says.

According to Li, the new study, which is detailed in Joule, could aid the development of standardized stability tests for how protons interact with OPV devices. Such tests already exist for c-Si and GaAs solar cells, but not for OPVs, he says.

The Michigan researchers say they will now be developing materials that combine high PCEs with strong resilience to proton exposure. “We will then use these materials to fabricate OPV devices that we will then test on CubeSats and spacecraft in real-world environments,” Li tells Physics World.

How international conferences can help bring women in physics together

International conferences are a great way to meet people from all over the world to share the excitement of physics and discuss the latest developments in the subject. But the International Conference on Women in Physics (ICWIP) offers more by allowing us to to listen to the experiences of people from many diverse backgrounds and cultures. At the same time, it highlights the many challenges that women in physics still face.

The ICWIP series is organized by the International Union of Pure and Applied Physics (IUPAP) and the week-long event typically features a mixture of plenaries, workshops and talks. Prior to the COVID-19 pandemic, the conferences were held in various locations across the world, but the last two have been held entirely online. The last such meeting – the 8th ICWIP run from India in 2023 – saw around 300 colleagues from 57 countries attend. I was part of a seven-strong UK contingent – at various stages of our careers – who gave a presentation describing the current situation for women in physics in the UK.

Being held solely online didn’t stop delegates fostering a sense of community or discussing their predicaments and challenges. What became evident during the week was the extent and types of issues that women from across the globe still have to contend with. One is the persistence of implicit and explicit gender bias in their institutions or workplaces. This, along with negative stereotyping of women, produces discrepancies between male and female numbers in institutions, particularly at postgraduate level and beyond. Women often end up choosing not to pursue physics later into their careers and being reluctant to take up leadership roles.

Much more needs to be done to ensure women are encouraged in their careers. Indeed, women often face challenging work–life balances, with some expected to play a greater role in family commitments than men, and have little support at their workplaces. One postdoctoral researcher at the 2023 meeting, for example, attempted to discuss her research poster in the virtual conference room while looking after her young children at home – the literal balancing of work and life in action.

A virtual presentation with five speakers' avatars stood in front of a slide showing their names — **Open forum** The author and co-presenters at the most recent International Conference on Women in Physics. Represented by avatars online, they gave a presentation on women in physics in the UK. (Courtesy: Chethana Setty)

To improve their circumstances, delegates suggested enhancing legislation to combat gender bias and improve institutional culture through education to reduce negative stereotypes. More should also be done to improve networks and professional associations for women in physics. Another factor mentioned at the meeting, meanwhile, is the importance of early education and issues related to equity of teaching, whether delivered face-to-face or online.

But women can face disadvantages other than their gender, such as socioeconomic status and identity, resulting in a unique set of challenges for them. This is the principle of intersectionality and was widely discussed in the context of problems in career progression.

In the UK, change is starting to happen. The Limit Less campaign by the Institute of Physics (IOP), which publishes Physics World, encourages students post 16 years old to study physics. The annual Conference for Undergraduate Women and Non-binary Physicists provides individuals with support and encouragement in their personal and professional development. There are also other initiatives such as the STEM Returner programme and the Daphne Jackson Trust for those wishing to return to a physics career. WISE Ten Steps contributes to supporting workplace culture positively and the Athena SWAN and the IOP’s new Physics Inclusion Award aims to improve women’s prospects.

As we now look forward to the next ICWIP there is still a lot more to do. We must ensure that women can continue in their physics careers while recognizing that intersectionality will play an increasingly significant role in shaping future equity, diversity and inclusion policies. It is likely that soon a new team will be sought from academia and industry, comprising of individuals at various career stages to represent the UK at the next ICWIP. Please do get involved if you are interested. Participation is not limited to women.

Women are doing physics in a variety of challenging circumstances. Gaining an international outlook of different cultural perspectives, as is possible at an international conference like the ICWIP, helps to put things in context and highlights the many common issues faced by women in physics. Taking the time to listen and learn from each other is critical, a process that can facilitate collaboration on issues that affect us all. Fundamentally, we all share a passion for physics, and endeavour to be catalysts for positive change for future generations.

This article was based on discussions with Sally Jordan from the Open University; Holly Campbell, UK Atomic Energy Authority; Josie C, AWE; Wendy Sadler and Nils Rehm, Cardiff University; and Sarah Bakewell and Miriam Dembo, Institute of Physics

Artisan, architect or artist: what kind of person are you at work?

We tend to define ourselves by the subjects we studied, and I am no different. I originally did physics before going on to complete a PhD in aeronautical engineering, which has led to a lifelong career in aerospace.

However, it took me quite a few years before I realized that there is more than one route to an enjoyable and successful career. I used to think that a career began at the “coal face” – doing things you were trained for or had a specialist knowledge of – before managing projects then products or people as you progressed to loftier heights.

Many of us naturally fall into one of three fundamental roles: artisan, architect or artist. So which are you?

At some point, I began to realize that while companies often adopt this linear approach to career paths, not everyone is comfortable with it. In fact, I now think that many of us naturally fall into one of three fundamental roles: artisan, architect or artist. So which are you?

Artisans are people who focus on creating functional, practical and often decorative items using hands-on methods or skills. Their work emphasizes craftmanship, attention to detail and the quality of the finished product. For scientists and engineers, artisans are highly skilled people who apply their technical knowledge and know-how. Let’s be honest: they are the ones who get the “real work” done. From programmers to machinists and assemblers, these are the people who create detailed designs and make or maintain a high-quality product.

Architects, on the other hand, combine vision with technical knowledge to create functional and effective solutions. Their work involves designing, planning and overseeing. They have a broader view of what’s happening and may be responsible for delivering projects. They need to ensure tasks are appropriately prioritized and keep things on track and within budget.

Architects also help with guiding on best practice and resolving or unblocking issues. They are the people responsible for ensuring that the end result meets the needs of users and, where applicable, comply with regulations. Typically, this role involves running a project or team – think principal investigator, project manager, software architect or systems engineer.

As for artists, they are the people who have a big picture view of the world – they will not have eyes for the finer details. They are less constrained by a framework and are comfortable working with minimal formal guidance and definition. They have a vision of what will be needed for the future – whether that’s new products and strategic goals or future skills and technology requirements.

Artists set the targets for how an organization, department or business needs to grow and they define strategies for how a business will develop its competitive edge. Artists are often leaders and chiefs.

Which type are you?

To see how these personas work in practice, imagine working for a power utility provider. If there’s a power outage, the artisans will be the people who get the power back on by locating and fixing damaged power lines, repairing substations and so on. They are practical people who know how to make things work.

The architect will be organizing the repair teams, working out who goes to which location, and what to prioritize, ensuring that customers are kept happy and senior leaders are kept informed of progress. The artist, meanwhile, will be thinking about the future. How, for example, can utilities protect themselves better from storm damage and what new technologies or designs can be introduced to make the supply more resilient and minimize disruption?

Predominantly artisans are practical, architects are tactical and artists are strategic but there is an overlap between these qualities. Artisans, architects and artists differ in their goals and methods, but the boundaries between them are blurred. Based on my gut experience as a physicist in industry, I’d say the breakdown between different skills is roughly as shown in the figure below.

Pie chart of personal attributes — **Varying values** Artisans, architects and artists don’t have only one kind of attribute but are practical, tactical and strategic in different proportions. The numbers shown here are based on the author’s gut feeling after working in industry for more than 30 years.

Now this breakdown is not hard and fast. To succeed in your career, you need to be creative, inventive and skilful – whatever your role. While working with your colleagues, you need to engage in common processes such as adhering to relevant standards, regulations and quality requirements to deliver quality solutions and products. But thinking of ourselves as artisans, architects or artists may explain why each of us is suited to a certain role.

Know your strengths

Even though we all have something of the other personas in us, what’s important is to know what your own core strength is. I used to believe that the only route for a successful career was to work through each of these personas by starting out as artisan, turning into an architect, and then ultimately becoming an artist. And to be fair, this is how many career paths are structured, which his why we’re often encouraged to think this way.

However, I have worked with people who liked “hands on” work so much, that didn’t want to move to a different role, even though it meant turning down a significant promotion. I also know others who have indeed moved between different personas, only to discover the new type of work did not suit them.

Trouble is, although it’s usually possible to retrace steps, it’s not always straightforward to do so. Quite why that should be the case is not entirely clear. It’s certainly not because people are unwilling to accept a pay cut, but more because changing tack is seen as a retrograde step for both employees and their employers.

To be successful, any team, department or business needs to not only understand the importance of this skills mix but also recognize it’s not a simple pipeline – all three personas are critical to success. So if you don’t know already, I encourage you to think about what you enjoy doing most, using your insights to proactively drive career conversations and decisions. Don’t be afraid to emphasize where your “value add” lies.

If you’re not sure whether a change in persona is right for you, seek advice from mentors and peers or look for a secondment to try it out. The best jobs are the ones where you can spend most of your time doing what you love doing. Whether you’re an artisan, architect or artist – the most impactful employees are the ones who really enjoy what they do.

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