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Sense, sensibility, and superconductors




Jonathan Monroe disagreed with his PhD supervisor—with respect. They needed to measure a superconducting qubit, a tiny circuit in which current can flow forever. The qubit emits light, which carries information about the qubit’s state. Jonathan and Kater intensify the light using an amplifier. They’d fabricated many amplifiers, but none had worked. Jonathan suggested changing their strategy—with a politeness to which Emily Post couldn’t have objected. Jonathan’s supervisor, Kater Murch, suggested repeating the protocol they’d performed many times.

“That’s the definition of insanity,” Kater admitted, “but I think experiment needs to involve some of that.”

I watched the exchange via Skype, with more interest than I’d have watched the Oscars with. Someday, I hope, I’ll be able to weigh in on such a debate, despite working as a theorist. Someday, I’ll have partnered with enough experimentalists to develop insight.

I’m partnering with Jonathan and Kater on an experiment that coauthors and I proposed in a paper blogged about here. The experiment centers on an uncertainty relation, an inequality of the sort immortalized by Werner Heisenberg in 1927. Uncertainty relations imply that, if you measure a quantum particle’s position, the particle’s momentum ceases to have a well-defined value. If you measure the momentum, the particle ceases to have a well-defined position. Our uncertainty relation involves weak measurements. Weakly measuring a particle’s position doesn’t disturb the momentum much and vice versa. We can interpret the uncertainty in information-processing terms, because we cast the inequality in terms of entropies. Entropies, described here, are functions that quantify how efficiently we can process information, such as by compressing data. Jonathan and Kater are checking our inequality, and exploring its implications, with a superconducting qubit.

I had too little experience to side with Jonathan or with Kater. So I watched, and I contemplated how their opinions would sound if expressed about theory. Do I try one strategy again and again, hoping to change my results without changing my approach? 

At the Perimeter Institute for Theoretical Physics, Masters students had to swallow half-a-year of course material in weeks. I questioned whether I’d ever understand some of the material. But some of that material resurfaced during my PhD. Again, I attended lectures about Einstein’s theory of general relativity. Again, I worked problems about observers in free-fall. Again, I calculated covariant derivatives. The material sank in. I decided never to question, again, whether I could understand a concept. I might not understand a concept today, or tomorrow, or next week. But if I dedicate enough time and effort, I chose to believe, I’ll learn.

My decision rested on experience and on classes, taught by educational psychologists, that I’d taken in college. I’d studied how brains change during learning and how breaks enhance the changes. Sense, I thought, underlay my decision—though expecting outcomes to change, while strategies remain static, sounds insane.

Does sense underlie Kater’s suggestion, likened to insanity, to keep fabricating amplifiers as before? He’s expressed cynicism many times during our collaboration: Experiment needs to involve some insanity. The experiment probably won’t work for a long time. Plenty more things will likely break. 

Jonathan and I agree with him. Experiments have a reputation for breaking, and Kater has a reputation for knowing experiments. Yet Jonathan—with professionalism and politeness—remains optimistic that other methods will prevail, that we’ll meet our goals early. I hope that Jonathan remains optimistic, and I fancy that Kater hopes, too. He prophesies gloom with a quarter of a smile, and his record speaks against him: A few months ago, I met a theorist who’d collaborated with Kater years before. The theorist marveled at the speed with which Kater had operated. A theorist would propose an experiment, and boom—the proposal would work.

Perhaps luck smiled upon the implementation. But luck dovetails with the sense that underlies Kater’s opinion: Experiments involve factors that you can’t control. Implement a protocol once, and it might fail because the temperature has risen too high. Implement the protocol again, and it might fail because a truck drove by your building, vibrating the tabletop. Implement the protocol again, and it might fail because you bumped into a knob. Implement the protocol a fourth time, and it might succeed. If you repeat a protocol many times, your environment might change, changing your results.

Sense underlies also Jonathan’s objections to Kater’s opinions. We boost our chances of succeeding if we keep trying. We derive energy to keep trying from creativity and optimism. So rebelling against our PhD supervisors’ sense is sensible. I wondered, watching the Skype conversation, whether Kater the student had objected to prophesies of doom as Jonathan did. Kater exudes the soberness of a tenured professor but the irreverence of a Californian who wears his hair slightly long and who tattooed his wedding band on. Science thrives on the soberness and the irreverence.

Who won Jonathan and Kater’s argument? Both, I think. Last week, they reported having fabricated amplifiers that work. The lab followed a protocol similar to their old one, but with more conscientiousness. 

I’m looking forward to watching who wins the debate about how long the rest of the experiment takes. Either way, check out Jonathan’s talk about our experiment if you attend the American Physical Society’s March Meeting. Jonathan will speak on Thursday, March 5, at 12:03, in room 106. Also, keep an eye out for our paper—which will debut once Jonathan coaxes the amplifier into synching with his qubit.



Singing plays a key role in thyroid cancer test




Vocal passive elastography
Vocal passive elastography uses ultrasound imaging to measure the speed of shear waves created in the thyroid by singing. (Courtesy: Steve Beuve)

A novel non-invasive test for thyroid cancer works by asking the patient to sing at the same time. Developed by researchers in France, the ultrasound-based procedure could determine the health of a patient’s thyroid and help detect any cancerous nodules.

Thyroid nodules are common, but only a small percentage of such nodules are cancerous. Typically, fine needle aspiration is to detect malignant tumours, but only about 5% of thyroid cancers are detected in this way. As the majority of thyroid cancers are hard, the presence of cancerous tissue in the thyroid will increase its stiffness. This makes elastography – a technique that measures tissue stiffness – an ideal candidate for detecting cancerous nodules.

In this study, the researchers designed an experiment based on passive elastography, which extracts elasticity from the natural vibrations in living tissues. Specifically, they exploit the shear waves generated naturally by the human voice to measure the elasticity of thyroid tissue – a technique they call vocal passive elastography (V-PE). They report their findings in Applied Physics Letters.

The researchers – from Université de Tours, CHU Dijon-Bourgogne and Université Bourgogne Franche-Comté – asked a volunteer to sing and maintain a monotonous tone at 150 Hz (roughly the frequency of the note D3), with a loudspeaker playing the same note to guide them. As the participant sings, vibrations in their trachea will induce shear waves in the surrounding thyroid gland.

The team tracked these waves using an ultrafast ultrasound probe placed horizontally against the surface of the neck. They then used correlation algorithms, based on time reversal methods initially employed in seismology, to compute the speed of the shear waves propagating through the thyroid.

If a tumour is present in the thyroid, the resulting increase in elasticity will cause the shear waves to accelerate. By superimposing a map of shear wave speed onto a thyroid ultrasound image, the researchers can mechanically characterize every point of the thyroid and find any abnormally stiff areas.

s) in the thyroid measured using V-PE. (Courtesy: Steve Beuve)”>s) in the thyroid measured using V-PE. (Courtesy: Steve Beuve)”>

Using their V-PE method in a volunteer, the team measured the shear wave speed at every point within a mask surrounding the thyroid, with a pixel resolution of 150 × 150 μm. The mean shear wave speed was 3.2 m/s, ranging from 0.7 to 8.8 m/s. To validate their V-PE algorithm, they also used an AIXplorer ultrasound scanner to measure shear wave speed in the volunteer’s thyroid. The measured values agreed well with the V-PE results.

The researchers point out that V-PE is quick and easy to perform. It does not need any specialized equipment to be added to the ultrasound scanner and requires only about 1 s of data acquisition. The longest step is the data analysis, but they have developed a computer program to perform the required computations automatically. The team is now working to improve the user friendliness of the computer interface, as well as investigating the potential of V-PE in other areas near the vocal tract, such as the brain.

“Developing non-invasive methods would reduce the stress of patients during their medical exams,” says first author Steve Beuve in a press announcement. “Having to sing during a medical exam can perhaps help release some of the nervous tension even more.”


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UK physicists begin life outside the EU — but remain in Horizon Europe




Two Arrows Textured with British and European Union Flags Pointing the Same Direction over Black And White Chessboard
Moving forward: A trade deal late last year between the UK and the EU came as a relief to many scientists as it allows continued British participation in the Horizon Europe programme. (Courtesy: iStock/microstockhub)

Following years of negotiations, delays and disagreements, on Christ­mas Eve the United Kingdom and the European Union finally agreed a trade deal following the UK’s exit from the EU. With the threat of a “no deal” looming large, the move ended years of uncertainty for UK scientists. The UK now joins Swit­zerland, Norway and 14 other non-EU nations as having “associated country” status of the seven-year €95bn Horizon Europe programme, which began last month. Yet many of the fine details of the deal still need to be ironed out, while 2020 also saw the end of most of the UK’s involvement in the Erasmus student exchange programme.

UK scientists have done excep­tionally well from EU research programmes in previous years. Estimates suggest the UK contrib­uted €5.4bn between 2007 and 2013 but received €8.8bn. As part of the Brexit deal, UK researchers remain eligible for Horizon Europe fund­ing on equivalent terms to their EU counterparts, with the UK’s finan­cial contribution being based on a share of its gross domestic product. Each year the UK’s contributions will be adjusted upwards or down­wards, based on how much it has paid in and taken out in previous years.

But crucially it will not be able to take out more than it pays in, mean­ing that the UK could lose access to a lot of extra funding. “The focus must now be on ensuring a fair and effective means to deliver appropri­ate association to EU science fund­ing programmes, such as Horizon Europe, outlined in the agreement,” says Royal Society president Adrian Smith. “Any delay in delivering such association will damage UK sci­ence.” UK researchers will not be able to take part in Horizon Europe until the details of the association have been agreed.

For UK science, the deal translates into getting notably less funding than before per pound sent to Brussels and, even more impor­tantly, a diminished influence in defining future priorities

Andre Geim

John Womersley, director-general of the European Spallation Source in Sweden, told Physics World that the deal provides most of what the research community had asked for, adding that “it’s a bit disappointing that there hasn’t been more trumpet­ing of this as a success”. He says that association with Horizon Europe was the highest priority for the UK’s research sector. “It comes as a huge relief to know that it will be imple­mented, especially after some nega­tive signals last autumn,” he says.

Indeed, in August more than 100 organizations and individuals rep­resenting the European scientific community had signed a statement urging the EU and the UK to com­promise due to fears the UK would lose its place in Horizon Europe. One of the signatories – Anton Zensus, director at the Max Planck Institute for Radio Astronomy in Bonn, Germany – told Physics World that he was very relieved by the deal, adding that it was “compromise we all have to live with”.

Yet others were not so positive. Physics Nobel laureate Andre Geim from the University of Manchester thinks that associated status will create “a bias against choosing Brits as programme leaders and against accepting UK-envisaged priorities” for funding. “As many people were so afraid of no-deal, this agree­ment might look like good news,” he told Physics World. “But make no mistake: for UK science, the deal translates into getting notably less funding than before per pound sent to Brussels and, even more impor­tantly, a diminished influence in defining future priorities.” Geim adds that the deal “is the price to pay  for jingoism” and will mean “more paperwork, less science”.

Nuclear co-operation

As part of the Brexit deal, the UK will also become an associated country in the Euratom programme. “On a practical level, an association means that the UK will still participate in all EU fusion programme activities,” says Ian Chapman, chief executive of the UK Atomic Energy Authority. Continued membership is subject to formal approval by both sides, but Chapman adds that “it is both par­ties’ firm intention that the protocol will be adopted at the earliest oppor­tunity”. The deal includes the UK’s ongoing participation in the ITER fusion experiment through member­ship of Fusion for Energy – the EU body responsible for its contribution to ITER. The Joint European Torus, which is based at the Culham Centre for Fusion Energy in Oxfordshire, is largely funded by Euratom and is cur­rently contracted to operate during 2021, with a further extension being discussed, according to Chapman.

Yet the UK will not be joining every Horizon Europe programme. UK researchers will, for example, be excluded from the European Innova­tion Council Fund. This new equity fund will provide grants to support start-ups and university spin-offs, but not those in the UK, according to the terms of the trade deal. The future of the UK’s participation in the Marie Skłodowska-Curie fel­lowships as well as the European Strategy Forum on Research and Innovation is also currently unknown and will require further negotiation.

The UK in addition failed to reach an agreement with the EU over its membership of the Erasmus student-exchange programme. The exit from the exchange scheme, which applies to all students except those in North­ern Ireland, came as a surprise as prime minister Boris Johnson had reassured MPs in January 2020 that there was no threat to the UK’s membership of Erasmus. But the two sides were reportedly unable to reach an agreement over costs. Last year a report by Universities UK Interna­tional found that Erasmus students contributed more than £240m a year profit to the UK economy.

Instead, the UK government announced its own £100m scheme, named after Alan Turing, to support UK students who wish to study abroad. The government said the new Turing scheme would provide funding for around 35 000 students to go overseas, starting in Septem­ber 2021, adding that it would target more students from disadvantaged backgrounds and areas. But it will not fund students from other coun­tries coming to the UK, cutting an important source of funding for UK universities.

UUKI director Vivienne Stern said that while the Erasmus announcement was “dis­appointing”, they were “pleased” the government has committed to a new UK programme to fund global mobility. “We now ask the UK gov­ernment to quickly provide clarity on this Erasmus domestic alternative, and that it be ambitious and fully funded,” she adds. Rachel Young­man, deputy chief executive of the Institute of Physics, which publishes Physics World, says that despite some positives in the deal, the institute is “disappointed” and “concerned” by the decision over Erasmus, adding that the IOP has “consistently argued for the importance of international exchange for university students”. 

The business view

Leaving the EU also means change for businesses with new tariffs, cus­toms arrangements, export regula­tions and other trading conditions. But the impact of the trade deal on the British industrial-physics community may take time to be fully understood given the global pandemic. Arnab Basu, founder and chief executive officer of the Kromek Group, which makes radi­ation-detection components and devices for medical imaging and nuclear security, told Physics World that so far the supply chain seems to be resilient. Kromek manufactures or sources most of its mechanical components in the UK and much of its electrical components in Asia and the US, meaning little impact from Brexit so far.

However, Basu says there “is some evidence of price increases for pur­chases from distributors ostensibly related to an uplift in logistics or administrative costs for goods com­ing in from the EU”. The company has also been advised of potential delays in shipment of goods manu­factured outside of the UK, but Basu adds “it is difficult to determine the extent to which that is down to the global pandemic as opposed to Brexit”.

Many physics-based compa­nies must also deal with additional regulations linked to the supply of items for medical therapeutics and imaging. “The biggest implication for our company is that we work in the diagnostics field and we now face two sets of regulations for any product we develop,” says Steve Self, commercial director of Stream Bio, a UK-based start-up that manufac­tures nanoparticles for applications in bioimaging. “This means that we have to do some additional work to qualify our products for sale in Europe,” he says.

Despite Geim’s disapproval over Brexit, he does see one main advan­tage in the deal – staying in the European Research Council (ERC). Indeed, there was good news from the ERC last month when UK sci­entists received the largest number of grants in the council’s first post- Brexit funding round. Eight of its 55 “proof of concept” grants – which explore the commercial potential of scientists’ work – will go to UK-based researchers. “The ERC was among a few prominent defenders of research quality as determined by peers rather than bureaucrats and politicians,” Geim says. “The UK’s participation in the ERC provides an important lifeline for fundamental research.”


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Radiology training course improves global access to medical imaging





A new educational course spearheaded by the Australian-based charity Radiology Across Borders (RAB) promises to improve patient access to imaging services worldwide. Aimed predominantly at those in the developing world or remote areas, it will focus on safety and interpreting common pathologies such as pneumonia, bleeds, trauma, meningitis, bone tumours and emergency conditions.

The International Certificate in Radiology Fundamentals (ICRF), a one-year online programme, is due to launch in February 2021 to allow any health professional to learn the basics of X-ray, ultrasound and CT in order to perform and read exams.

Hands-on training

Besides coursework, there will be regular meetings between the course’s tutors and the 50 participants. The final ICRF will be attained on completion of the course. It will be accredited by a major institution and represent the equivalent knowledge base of a second-year registrar in a developed country.

“This is going to make a huge difference to radiology education in developing nations. We’ve already had 185 individual expressions of interest from 60 countries,” noted radiologist and RAB founder Suresh de Silva, pointing to enquiries from the Indo-Pacific, Mongolia, Vietnam, Colombia, Africa, Algeria, Kenya and Ethiopia.

He also noted there had been applications from the UK, Israel, Ireland, Germany, Serbia, Hungary, Australia, New Zealand and North America, though these nations will not receive priority in the first year. Health professionals may eventually use the certificate as a steppingstone to further radiology specialization training, he said.

How the scheme works

Each participant from developing nations will pay a total of A$500 (€320) for the entire year’s course, though there is RAB funding for those that can’t afford it, noted de Silva. The fee will help sustain the project longer term. It is estimated that the first year of operation will cost the organization close to around A$100,000 (€64,000) for the IT platform and project coordination, and this isn’t factoring in pro bono work by the 14 Australian RAB members who helped create the content and will serve as tutors, as well as the four volunteer Canadian medical students.

Furthermore, RAB estimates that the four years of research and development of ICRF have cost over a million dollars, including the IT and volunteer work.

George Koulouris

“Importantly, this ICRF initiative will lead to other projects. For example, some participants will have access to imaging units while others won’t. Companies involved with RAB projects both financially and logistically, such as Siemens Healthineers, hopefully will come to the fore for the provision of such equipment to those that complete the training, particularly in countries where RAB doesn’t yet send its own radiologists to undertake field work,” de Silva noted.

While this project was formulated by RAB over four years, the core part of the content comes from the UK Royal College of Radiologists’ (RCR) online Radiology-Integrated Training Initiative (R-ITI) course (eIntegrity). Input has also come from, a wiki-based collaborative educational radiology web resource, and the many RAB radiologists who contributed around 30% of the programme by providing their own material, including video tutorials.

Bruce Forster, head of radiology at University of British Colombia (UBC) in Canada, and Richard Mendelson, emeritus consultant at the Royal Perth Hospital in Australia, have also been instrumental in the development of the ICRF, de Silva added.

Ongoing projects

RAB is continuing its existing educational programmes in the form of global teleconferences on different themes; the RABinars for radiologists will take place every three weeks in 2021 and the RABitts conferences for imaging technologists will occur monthly. These are broadcast to 400 sites in 58 countries.

The charity also aims to provide a timely response to new topics that arise, such as COVID-19, creating lectures and Q&A sessions that can be mailed out to its recipients in developing nations within a week.

RAB’s 2019-created TIDES project provides teleradiology for disaster events, screening and second opinions in several target countries. Currently, TIDES is focusing on second opinions in Samoa and the Cook Islands, where there is no local radiologist and doctors typically have struggled to decide whether to send patients to New Zealand or keep them in the country. Valuable second opinions now are furnished by 26 RAB radiologists across Australia and New Zealand, and the organization is looking to extend this network to include radiologists in other countries, thus expanding services beyond Samoa and the Cook Islands.

As difficult as 2020 was due to the pandemic, RAB started its pilot one-to-one mentorship programme, whereby sonographers and radiographers in developed nations teamed up with their counterparts in developing countries. In 2021, 30 mentors and 30 mentorees registered for the programme, and this will continue in the first part of 2021 with a new intake of participants.

Women’s health has also been under the spotlight with the charity’s VITAL programme. This onsite project involved six sonographers who in 2018 and 2019 were sent to provide a week of hands-on ultrasound training in the Indo-Pacific region, Fiji and Vietnam for breast, obstetrics and gynaecology.

VITAL programme

This training was so successful that the plan was to extend it to Mongolia and the Cook Islands in 2020. While the plans were cancelled due to the pandemic, RAB provided online training notes and in 2021 will launch virtual training through weekend teleconferences that will also extend to paediatrics and cover topics such as common abdominal and chest conditions, and complications.

“COVID has hampered much of the face-to-face work that RAB carries out across 12 nations including Cambodia, Mongolia, Sri Lanka, Laos, Vietnam, Myanmar and six countries in the Pacific, but projects that have turned virtual for 2021 are planned to return onsite in 2022,” de Silva said.

Individuals and sites can still access free video content in the RAB library, he added. To date, there have been 1500 lessons provided by 70 to 80 contributing RAB members and 26,000 hits of these in the last 10 months.

RAB is now looking for colleges in Europe or elsewhere who may be interested in providing material for this library. These colleges will be credited for the content and become part of the charity’s network. “Our aim is to make the library the best free resource available,” de Silva noted.

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Quantum connection is made by flying drones




Drone quantum networkNanjing University in China and with further improvements it could lead to flexible, highly configurable networks for quantum cryptography.

Quantum communication techniques such as quantum key distribution (QKD) use the laws of quantum mechanics to allow to parties to share cryptography keys with complete security — at least in principle. One implementation of QKD involves sharing the key by the transmission and detection of entangled photons – and a crucial feature of this approach is that the parties can tell if an eavesdropper has intercepted the photons. Once the secrecy of the key is established it can be used to exchange encrypted messages using a conventional communications network.

Today, most quantum communications are done via optical fibres. While this is practical over short distances – say in a metropolitan area – it is difficult to link parties over longer distances because significant signal losses occur in fibres due to photon scattering. Alternatively, photons can be sent up to satellites and then relayed to a distant ground station. While effective, this space-based approach requires costly and inflexible infrastructure, which makes it currently impractical for widespread use.

Inexpensive and flexible

So hence the interest in flying drones, which the Nanjing team used to carry sources of entangled photons in a link that connected two parties on the ground. As well as being relatively inexpensive, drones can be deployed quickly to create a flexible, dynamic network that changes based on need.

A major challenge for the team was how to contend with the diffraction of photons as they travel through the air. Diffraction causes the wavefront of the photon to spread out as it propagates, making it difficult to fully capture the photons using a single-photon detector attached to a telescope.

To reduce the effect of diffraction, Liu and colleagues introduced a second drone to act as a relay between photon source and detection station. After receiving a diffracted photon from the first drone, the second drone uses a specialized optical fibre to refocus the photon towards a receiving telescope on the ground.

In the team’s experiment, the two drones were flown 200 m apart, with each drone 400 m away from a detection station. Overall, the two detection stations, named Alice and Bob, were separated by 1 km. When the researchers generated an entangled pair of photons on the drone nearest to Alice, 25% of the photons were detected by Alice. Bob, however, could only detect 4% of the photons sent via the relay drone. Liu’s team confirmed that these photons were entangled using standard Bell inequality tests.

Although the transmission losses of these signals are still too great to compete with existing quantum communication systems, the researchers hope that the low cost, scalable nature of drone technology will enable rapid improvements soon. The team now plans to expand the size of their network to include multiple drones – which could facilitate communications between large, dynamic networks of users, even within cities. If their technique becomes commercially viable, it could make drone networks an important supplement to fibre optics and satellite networks.

The research is described in Physical Review Letters.


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