Aurelia Butler

When a family of five-ton elephants stomps and chomps its waythrough your crops, there’s only one winner. And in the central African nation of Gabon, farmers are getting fed up with the giant animals trampling their fields — and their livelihoods.
In conservation terms, Gabon is a success story — protected areas and tough anti-poaching measures have allowed the numbers of critically endangered African forest elephants to stabilize. But with food prices rising, anti-elephant protests have been spiking too. “Some people cannot farm anymore — the elephants are eating so much of their crops,” Gabon’s environment minister Lee White told Reuters in 2022. “It has become a political issue and is eroding support for conservation and for the president (and) government.”
As Gabon’s leaders have learned, balancing conservation and agriculture isn’t easy: tilt policies in favor of farmers, and important habitats or species could be lost; tip efforts toward animals or land, and people may lose their livelihoods. Paying farmers to support the environment might seem like an easy answer — incentivizing them to conserve habitats. But a new study led by Andrew Reid Bell, a Boston University College of Arts & Sciences assistant professor of Earth & environment, has found payments don’t always reconcile the tension between agricultural production and the planet’s health.
With an international team of researchers, he used video games to test how farmers around the world react when faced with conservation dilemmas — like traipsing elephants in Gabon, hungry geese in Scotland, and crop pests in Cambodia. For the most part, payments designed to motivate eco-friendly behavior weren’t a reliable panacea: if they boosted pro-conservation work, they usually dented agricultural outputs. The study did, though, discover one seemingly surefire way of improving conservation and production: including more women in decision-making. Their involvement boosted cooperation between farmers on environmental issues and increased output. The results were published in Communications Earth & Environment.
“It informs this bigger story of finding ways to better empower women in agricultural contexts around the world,” says Bell.
Playing Games, Testing Dilemmas
To see how farmers and pastoralists behaved when confronted with a conservation predicament, Bell designed and built three games using the modeling tool NetLogo. Each game posed a different dilemma for players: GooseBump, decide to let wildlife damage crops, scare animals onto other farms, or use lethal control; NonCropShare, choose between using pesticides or natural pest control; and SharedSpace, balance growing crops while conserving forest and managing fallow land. The multiplayer games were played on tablets in seven countries, from the Orkney Islands off the northernmost tip of Scotland to Madagascar to Vietnam.

“We were looking at how players sharing a space will coordinate and any player has equal opportunity to lead the group, follow, or encourage a particular result,” says Bell, a resource ecology and management expert who specializes in building computer models and behavioral experiments to examine issues like agricultural development and water use.
It turned out that pro-environment payments can work in some situations — usually if there’s a clear agricultural benefit, such as when neighboring farmers coordinate on leaving areas fallow, boosting soil resiliency and, therefore, their overall crop yield. But when the benefits take time or don’t quickly improve output, payments aren’t effective: increased biodiversity might help society in the long term, but doesn’t change this year’s harvest, or next year’s.
“The challenge in many lower-income environments is that a lot of the payoffs to conservation agriculture emerge on four- to eight-year time horizons,” says Bell, “which is often beyond the planning horizon of farmers who are thinking two or three months ahead, meeting more immediate needs. It’s a mismatch.”
The first program the team created was NonCropShare, a pest control game that was played by farmers in Cambodia and Vietnam.
“You could do well by just spraying everything and avoiding pest damage,” says Bell, “but you could do equally well by coordinating on maintaining natural enemies — parasitic wasps, spiders, or dragonflies that would eat the pests. The challenge with that coordinated solution is that if anybody defected, everybody else would be worse off. The question was, how much do we have to incentivize that pro-environmental solution to tip the balance?”
The answer depended on the country. In Vietnam, payments nudged farmers into cooperation, while in Cambodia they just made things worse. “The approach to farming — in the game, at least — wasn’t a good match for the payments” in Cambodia, says Bell, “and the mix of strategies that people employed when we offered payments left the landscapes worse off than if we hadn’t offered anything.” The other two games reflected the overall trend.

From Mario Kart to Human Behavior
It’s not the first time Bell has mixed video games and conservation studies. In one past paper, he drew lessons from Nintendo’s Mario Kart, looking at the way it gives better bonuses to dawdling players to keep races even. He says games are useful as an experimental tool, too, allowing researchers and policymakers to trial a theory or an approach to an issue when a field test is either impractical or too costly. And they help him dig into human behavior and decision-making in deeper ways than a survey or interview can: “It’s really common people can’t tell you what they’re thinking,” says Bell, who’s also affiliated with the BU Center on Forced Displacement, “or how they do something, or they don’t want to.”
And in conservation, some of the dilemmas faced by farmers aren’t exactly polite dinner table topics — not many people will admit to killing wildlife, but they might debate the action in an impersonal video game.
“Dynamic games like this can help desensitize illegal activities, such as lethal control or forest clearing, in a way conventional tools cannot,” says Sarobidy Rakotonarivo, an author on the paper and environmental socioeconomist based in Madagascar. “These are often criminalized activities that farmers are unwilling to talk about for fear of prosecution. The games provide a safer environment to get them to talk openly.”
When it comes to our changing planet, says Bell, we have a lot of big data — satellite images, gauges on land, sea, and air — but not nearly as much information on human decision-making.
“We can talk about sea surface temperature or rainfall anomalies, about deviation from a mean, but we don’t have that with social data — we don’t know much about what people do,” he says. With one exception: when disaster, like a famine, strikes. Then researchers descend and grab as much information as possible about what went wrong. “But we miss all these stories where things are going just fine, we miss our ability to explain why that is. So, we need ways to better engage with people to capture their decisions.”
Empower Women
Including women in farming groups was one human factor that made a lot of things go right, according to Bell’s study. Whenever a group had increased gender diversity, production and pro-environment outcomes improved. In their paper, the researchers write that “mixed gender groups may lead to better natural resource management.” They also showed that when the players built strong relationships and trusted each other, conservation efforts got a boost.
“We need to be better at empowering women in agricultural contexts,” says Bell. “It’s hard, because, in part, you see all these cases where people invest in a crop that’s traditionally a women’s crop, it succeeds, then becomes a men’s crop.”
The International Food Policy Research Institute — whose senior research fellow Wei Zhang was a coauthor on the latest study — has found protecting women’s rights to own land, improving their access to credit and financial services, and giving them more decision-making power can all help.
And, adds Rakotonarivo, an African Research Initiative for Scientific Excellence research fellow, we also need to step up when it comes to listening to — and trusting — the people most impacted by conservation policies.
“Small-scale rural farmers, although often portrayed as having low levels of education, are capable of wise choices,” she says. “They are not the key obstacles to conservation as often assumed. Obstacles may be simply broader social barriers, such as very low agricultural productivity, that need to be addressed by other types of programs.”
Rakotonarivo says that ignoring farmers when developing pro-environment interventions will only lead to failure; if their needs aren’t considered, programs “might fail to mitigate conservation conflicts through lack of engagement, uptake, and follow-through.” Although many problems — farmers killing pest animals or clearing forests — are “commonly framed as human-wildlife conflicts,” she says, the issues may be better addressed by looking at the “more complex social conflicts between different social groups.”
In their paper, the researchers recommend policymakers consider programs that have both conservation and production goals, rather than just one of those goals, or that include bonuses for cooperation among groups of farmers. They also highlight improved access to insurance programs that cover the risks of pro-environment efforts, ensuring payouts, for example, when tigers or lions raid livestock. But most of all, they write, rather than being prescriptive with program suggestions, “we only wish to highlight the challenges of aligning encouragements simultaneously with environment and livelihood goals.”
There is one innovative, nature-based solution in the paper though that might be of particular interest to the farmers of Gabon: bee fences. These makeshift, homespun barriers are hung with beehives every 10 meters or so. If an animal tries to crash through, the bees quickly give them a reason to turn around. And while popular culture might show elephants cowering when a mouse scuttles by, it’s bees they really don’t like. If the elephants, preoccupied by bees, don’t trample and gobble the crops, the farmers are more likely to help protect the animals.
“Conservation often comes at the cost of rural livelihoods,” says Rakotonarivo. “Policymakers, and especially the conservation community, need to be deliberate about the joint people and environment goals of an intervention.”
This study was primarily supported by the CGIAR Research Program on Water, Land, and Ecosystems; the CGIAR Research Program on Policies, Institutions, and Markets; and the European Research Council. The research team also included Apurva Bhargava, New York University; A. Bradley Duthie and Adams Kipchumba, University of Stirling, Scotland; Becca Sargent, Newcastle University, England; and Spike Lewis, Bangor University, Wales. More

For the first time, scientists at the University of Sydney and the University of Basel in Switzerland have demonstrated the ability to manipulate and identify small numbers of interacting photons — packets of light energy — with high correlation.
This unprecedented achievement represents an important landmark in the development of quantum technologies. It is published today in Nature Physics.
Stimulated light emission, postulated by Einstein in 1916, is widely observed for large numbers of photons and laid the basis for the invention of the laser. With this research, stimulated emission has now been observed for single photons.
Specifically, the scientists could measure the direct time delay between one photon and a pair of bound photons scattering off a single quantum dot, a type of artificially created atom.
“This opens the door to the manipulation of what we can call ‘quantum light’,” Dr Sahand Mahmoodian from the University of Sydney School of Physics and joint lead author of the research said.
Dr Mahmoodian said: “This fundamental science opens the pathway for advances in quantum-enhanced measurement techniques and photonic quantum computing.”
By observing how light interacted with matter more than a century ago, scientists discovered light was not a beam of particles, nor a wave pattern of energy — but exhibited both characteristics, known as wave-particle duality.

The way light interacts with matter continues to enthral scientists and the human imagination, both for its theoretical beauty and its powerful practical application.
Whether it be how light traverses the vast spaces of the interstellar medium or the development of the laser, research into light is a vital science with important practical uses. Without these theoretical underpinnings, practically all modern technology would be impossible. No mobile phones, no global communication network, no computers, no GPS, no modern medical imaging.
One advantage of using light in communication — through optic fibres — is that packets of light energy, photons, do not easily interact with each other. This creates near distortion-free transfer of information at light speed.
However, we sometimes want light to interact. And here, things get tricky.
For instance, light is used to measure small changes in distance using instruments called interferometers. These measuring tools are now commonplace, whether it be in advanced medical imaging, for important but perhaps more prosaic tasks like performing quality control on milk, or in the form of sophisticated instruments such as LIGO, which first measured gravitational waves in 2015.

The laws of quantum mechanics set limits as to the sensitivity of such devices.
This limit is set between how sensitive a measurement can be and the average number of photons in the measuring device. For classical laser light this is different to quantum light.
Joint lead author, Dr Natasha Tomm from the University of Basel, said: “The device we built induced such strong interactions between photons that we were able to observe the difference between one photon interacting with it compared to two.
“We observed that one photon was delayed by a longer time compared to two photons. With this really strong photon-photon interaction, the two photons become entangled in the form of what is called a two-photon bound state.”
Quantum light like this has an advantage in that it can, in principle, make more sensitive measurements with better resolution using fewer photons. This can be important for applications in biological microscopy when large light intensities can damage samples and where the features to be observed are particularly small.
“By demonstrating that we can identify and manipulate photon-bound states, we have taken a vital first step towards harnessing quantum light for practical use,” Dr Mahmoodian said.
“The next steps in my research are to see how this approach can be used to generate states of light that are useful for fault-tolerant quantum computing, which is being pursued by multimillion dollar companies, such as PsiQuantum and Xanadu.”
Dr Tomm said: “This experiment is beautiful, not only because it validates a fundamental effect — stimulated emission — at its ultimate limit, but it also represents a huge technological step towards advanced applications.
“We can apply the same principles to develop more-efficient devices that give us photon bound states. This is very promising for applications in a wide range of areas: from biology to advanced manufacturing and quantum information processing.”
The research was a collaboration between the University of Basel, Leibniz University Hannover, the University of Sydney and Ruhr University Bochum.
The lead authors are Dr Natasha Tomm from the University of Basel and Dr Sahand Mahmoodian at the University of Sydney, where he is an Australian Research Council Future Fellow and Senior Lecturer.
The artificial atoms (quantum dots) were fabricated at Bochum and used in experiment performed in the Nano-Photonics Group at the University of Basel. Theoretical work on the discovery was carried out by Dr Mahmoodian at the University of Sydney and Leibniz University Hannover. More

University of Minnesota Twin Cities researchers, along with a team at the National Institute of Standards and Technology (NIST), have developed a breakthrough process for making spintronic devices that has the potential to become the new industry standard for semiconductors chips that make up computers, smartphones, and many other electronics. The new process will allow for faster, more efficient spintronics devices that can be scaled down smaller than ever before. 
The researchers’ paper is published in Advanced Functional Materials, a peer-reviewed, top-tier materials science journal.
“We believe we’ve found a material and a device that will allow the semiconducting industry to move forward with more opportunities in spintronics that weren’t there before for memory and computing applications,” said Jian-Ping Wang, senior author of the paper and professor and Robert F. Hartmann Chair in the University of Minnesota Department of Electrical and Computer Engineering. “Spintronics is incredibly important for building microelectronics with new functionalities.”
Wang said Minnesota has been leading this effort in a big way for more than 10 years with strong support by the Semiconductor Research Corporation (SRC), Defense Advanced Research Projects Agency (DARPA), and the National Science Foundation (NSF).
Wang’s team has also worked with University of Minnesota Technology Commercialization and NIST to patent this technology, along with several other patents related to this research. This discovery also opens up a new vein of research for designing and manufacturing spintronic devices for the next decade.
“This means Honeywell, Skywater, Globalfoundries, Intel, and companies like them can integrate this material into their semiconductor manufacturing processes and products,” Wang said. “That’s very exciting because engineers in the industry will be able to design even more powerful systems.”
The semiconductor industry is constantly trying to develop smaller and smaller chips that can maximize energy efficiency, computing speed, and data storage capacity in electronic devices. Spintronic devices, which leverage the spin of electrons rather than the electrical charge to store data, provide a promising and more efficient alternative to traditional transistor-based chips. These materials also have the potential to be non-volatile, meaning they require less power and can store memory and perform computing even after you remove their power source.

Spintronic materials have been successfully integrated into semiconductor chips for more than a decade now, but the industry standard spintronic material, cobalt iron boron, has reached a limit in its scalability. Currently, engineers are unable to make devices smaller than 20 nanometers without losing their ability to store data.
The University of Minnesota researchers have circumvented this problem by showing that iron palladium, an alternative material to cobalt iron boron that requires less energy and has the potential for more data storage, can be scaled down to sizes as small as five nanometers.
And, for the first time, the researchers were able to grow iron palladium on a silicon wafer using an 8-inch wafer-capable multi-chamber ultrahigh vacuum sputtering system, a one-of-a-kind piece of equipment among academic institutions across the country and only available at the University of Minnesota.
“This work is showing for the first time in the world that you can grow this material, which can be scaled down to smaller than five nanometers, on top of a semiconductor industry-compatible substrate, so-called CMOS+X strategies,” said Deyuan Lyu, first author on the paper and a Ph.D. student in the University of Minnesota Department of Electrical and Computer Engineering.
“Our team challenged ourselves to elevate a new material to manufacture spintronic devices needed for the next generation of data-hungry apps,” said Daniel Gopman, a staff scientist at NIST and one of the key contributors to the research. “It will be exciting to see how this advance drives further growth of spintronics devices within the semiconductor chip technology landscape.”
This research was funded by a $4 million, four-year grant from DARPA and in part by NIST; SMART, one of seven centers of nCORE, an SRC program; and NSF.
In addition to Wang, Gopman, and Lyu, the research team comprised University of Minnesota researchers across the College of Science and Engineering, including Department of Electrical and Computer Engineering researchers Qi Jia, William Echtenkamp, and Brandon Zink; Department of Mechanical Engineering researcher Dingbin Huang and Associate Professor Xiaojia Wang; and Characterization Facility researchers Javier García-Barriocanal, Geoffrey Rojas, and Guichuan Yu. National Institute of Standards and Technology researcher Jenae Shoup also contributed to the research. More

Security gaps exist not only in software, but also directly in hardware. Attackers might deliberately have them built in in order to attack technical applications on a large scale. Researchers at Ruhr University Bochum, Germany, and the Max Planck Institute for Security and Privacy (MPI-SP) in Bochum are exploring methods of detecting such so-called hardware Trojans. They compared construction plans for chips with electron microscope images of real chips and had an algorithm search for differences. This is how they detected deviations in 37 out of 40 cases.
The team at the CASA Cluster of Excellence (short for Cyber Security in the Age of Large-Scale Adversaries), headed by Dr. Steffen Becker, and the MPI-SP team headed by Endres Puschner, will present their findings at the IEEE Symposium on Security and Privacy, which will take place in San Francisco from 22 to 25 May 2023. The research was conducted in collaboration with Thorben Moos from the Université catholique de Louvain (Belgium) and the Federal Criminal Police Office in Germany.
The researchers released all images of the chips, the design data as well as the analysis algorithms online for free so that other research groups can use the data to conduct further studies.
Manufacturing plants as a gateway for hardware Trojans
These days, electronic chips are integrated into countless objects. They are more often than not designed by companies that don’t operate their own production facilities. The construction plans are therefore sent to highly specialised chip factories for production. “It’s conceivable that tiny changes might be inserted into the designs in the factories shortly before production that could override the security of the chips,” explains Steffen Becker and gives an example for the possible consequences: “In extreme cases, such hardware Trojans could allow an attacker to paralyse parts of the telecommunications infrastructure at the push of a button.”
Identifying differences between chips and construction plans
Becker and Puschner’s team analysed chips produced in the four modern technology sizes of 28, 40, 65 and 90 nanometres. For this purpose, they collaborated with Dr. Thorben Moos, who had designed several chips as part of his PhD research at Ruhr University Bochum and had them manufactured. Thus, the researchers had both the design files and the manufactured chips at their disposal. They obviously couldn’t modify the chips after the fact and build in hardware Trojans. And so they employed a trick: rather than manipulating the chips, Thorben Moos changed his designs retroactively in order to create minimal deviations between the construction plans and the chips. Then, the Bochum researchers tested if they could detect these changes without knowing what exactly they had to look for and where.

In the first step, the team at Ruhr University Bochum and MPI-SP had to prepare the chips using complex chemical and mechanical methods in order to take several thousand images of the lowest chip layers with a scanning electron microscope. These layers contain several hundred thousand of the so-called standard cells that carry out logical operations.
“Comparing the chip images and the construction plans turned out to be quite a challenge, because we first had to precisely superimpose the data,” says Endres Puschner. In addition, every little impurity on the chip could block the view of certain sections of the image. “On the smallest chip, which is 28 nanometres in size, a single speck of dust or a hair can obscure a whole row of standard cells,” stresses the IT security expert.
Almost all manipulations detected
The researchers used image processing methods to carefully match standard cell for standard cell and looked for deviations between the construction plans and the microscopic images of the chips. “The results give cause for cautious optimism,” as Puschner sums up the findings. For chip sizes of 90, 65 and 40 nanometres, the team successfully identified all modifications. The number of false-positive results totalled 500, i.e. standard cells were flagged as having been modified, although they were in fact untouched. “With more than 1.5 million standard cells examined, this is a very good rate,” says Puschner. It was only with the smallest chip of 28 nanometres that the researchers failed to detect three subtle changes.
Higher detection rate through clean room and optimised algorithms
A better recording quality could remedy this problem in the future. “Scanning electron microscopes do exist that are specifically designed to take chip images,” points out Becker. Moreover, using them in a clean room where contamination can be prevented would increase the detection rate even further.
“We also hope that other groups will use our data for follow-up studies,” as Steffen Becker outlines potential future developments. “Machine learning could probably improve the detection algorithm to such an extent that it would also detect the changes on the smallest chips that we missed.” More

Researchers from the University of Technology Sydney (UTS) have developed biosensor technology that will allow you to operate devices, such as robots and machines, solely through thought control.
The advanced brain-computer interface was developed by Distinguished Professor Chin-Teng Lin and Professor Francesca Iacopi, from the UTS Faculty of Engineering and IT, in collaboration with the Australian Army and Defence Innovation Hub.
As well as defence applications, the technology has significant potential in fields such as advanced manufacturing, aerospace and healthcare — for example allowing people with a disability to control a wheelchair or operate prosthetics.
“The hands-free, voice-free technology works outside laboratory settings, anytime, anywhere. It makes interfaces such as consoles, keyboards, touchscreens and hand-gesture recognition redundant,” said Professor Iacopi.
“By using cutting edge graphene material, combined with silicon, we were able to overcome issues of corrosion, durability and skin contact resistance, to develop the wearable dry sensors,” she said.
A new study outlining the technology has just been published in the peer-reviewed journal ACS Applied Nano Materials. It shows that the graphene sensors developed at UTS are very conductive, easy to use and robust.
The hexagon patterned sensors are positioned over the back of the scalp, to detect brainwaves from the visual cortex. The sensors are resilient to harsh conditions so they can be used in extreme operating environments.
The user wears a head-mounted augmented reality lens which displays white flickering squares. By concentrating on a particular square, the brainwaves of the operator are picked up by the biosensor, and a decoder translates the signal into commands.
The technology was recently demonstrated by the Australian Army, where soldiers operated a Ghost Robotics quadruped robot using the brain-machine interface. The device allowed hands-free command of the robotic dog with up to 94% accuracy.
“Our technology can issue at least nine commands in two seconds. This means we have nine different kinds of commands and the operator can select one from those nine within that time period,” Professor Lin said.
“We have also explored how to minimise noise from the body and environment to get a clearer signal from an operator’s brain,” he said.
The researchers believe the technology will be of interest to the scientific community, industry and government, and hope to continue making advances in brain-computer interface systems. More

Researchers have devised a new concept of superconducting microwave low-noise amplifiers for use in radio wave detectors for radio astronomy observations, and successfully demonstrated a high-performance cooled amplifier with power consumption three orders of magnitude lower than that of conventional cooled semiconductor amplifiers. This result is expected to contribute to the realization of large-scale multi-element radio cameras and error-tolerant quantum computers, both of which require a large number of low-noise microwave amplifiers.
The devise they used is called an SIS mixer. The SIS mixer is named after its structure, a very thin film of insulator material sandwiched between two layers of superconductors (S-I-S). In a radio telescope, cosmic radio waves collected by an antenna are fed into an SIS mixer, and the output signal is amplified by low-noise semiconductor amplifiers. An SIS mixer operates in a very low temperature environment, as low as 4 Kelvin (-269 degrees Celsius), and the amplifiers are also operated at that temperature.
To improve the performance of radio telescopes, researchers are developing a large-format radio camera equipped with 2D arrays of SIS mixers and amplifiers. However, the power consumption is a limiting factor. The typical power consumption of a semiconductor amplifier is about 10 mW, and by assembling 100 sets of detectors, the total power consumption reaches the maximum cooling capability of a 4 Kelvin refrigerator.
The research team led by Takafumi Kojima, an associate professor at the National Astronomical Observatory of Japan (NAOJ), has come up with a simple but innovative idea to realize a superconductor amplifier by connecting two SIS mixers. The team exploits the basic functions of the SIS mixer: frequency conversion and signal amplification. “The most important point is that the power consumption of an SIS mixer is, in principle, as low as microwatts,” says Kojima. “This is three orders of magnitude less than that of a cooled semiconductor amplifier.”
After obtaining successful preliminary results in 2018, the team advanced both the theoretical studies of the system and the physical implementation of its various components. In the end, the research team optimized the system and realized an “SIS amplifier” with 5 — 8 dB (three to six times) gain below the frequency of 5 GHz and a typical noise temperature of 10 K, which is comparable to the current cooled semiconductor amplifiers such as HEMT and HBT, but with much lower power consumption.
“By changing the configuration of the components, we can further improve the gain and low-noise performance of an SIS amplifier,” explains Kojima. “The idea of connecting two SIS mixers has broader applications for making various electronics that have functions other than amplification.”
Interestingly, this low-noise, low-power-consumption amplifier is also highly anticipated for large-scale error-tolerant quantum computers. Currently available quantum computers are small-scale with less than 100 qubits, but larger-scale, error-tolerant general-purpose quantum computers will require more than 1 million qubits. To handle a large number of qubits, a large number of amplifiers must also be installed, and dramatic reductions in amplifier power consumption are needed.
NAOJ has experience in the development of superconducting receivers for a number of radio telescopes, including NAOJ’s Nobeyama 45-meter Radio Telescope, which started operation in 1982. NAOJ is also currently working to upgrade the superconducting receivers to improve the performance of the Atacama Large Millimeter/submillimeter Array (ALMA), which is operated in the Republic of Chile in cooperation with East Asia, Europe, and North America. Of the 10 types of receivers (corresponding to 10 different frequency bands) currently installed on ALMA, three were developed by NAOJ, and the SIS chips at the heart of these receivers were also developed and produced in the cleanroom of the NAOJ Advanced Technology Center (ATC). The NAOJ ATC continues to promote research on the miniaturization and integration of superconducting circuits, not only for the realization of more powerful radio telescopes, but also for their potential as the basis of various technologies that will support society in the new era, such as quantum computing. More

The development of new information and communication technologies poses new challenges to scientists and industry. Designing new quantum materials — whose exceptional properties stem from quantum physics — is the most promising way to meet these challenges. An international team led by the University of Geneva (UNIGE) and including researchers from the universities of Salerno, Utrecht and Delft, has designed a material in which the dynamics of electrons can be controlled by curving the fabric of space in which they evolve. These properties are of interest for next-generation electronic devices, including the optoelectronics of the future. These results can be found in the journal Nature Materials.
The telecommunications of the future will require new, extremely powerful electronic devices. These must be capable of processing electromagnetic signals at unprecedented speeds, in the picosecond range, i.e. one thousandth of a billionth of a second. This is unthinkable with current semiconductor materials, such as silicon, which is widely used in the electronic components of our telephones, computers and game consoles. To achieve this, scientists and industry are focusing on the design of new quantum materials.
Thanks to their unique properties — especially the collective reactions of the electrons that compose them — these quantum materials could be used to capture, manipulate and transmit information-carrying signals (for example photons, in the case of quantum telecommunications) within new electronic devices. Moreover, they can operate in electromagnetic frequency ranges that have not yet been explored and would thus open the way to very high-speed communication systems.
A warp drive
”One of the most fascinating properties of quantum matter is that electrons can evolve in a curved space. The force fields, due to this distortion of the space inhabited by the electrons, generate dynamics totally absent in conventional materials. This is an outstanding application of the principle of quantum superposition,” explains Andrea Caviglia, full professor at the Department of Quantum Matter Physics in the Faculty of Science of the UNIGE and last author of the study.
After an initial theoretical study, the international team of researchers from the Universities of Geneva, Salerno, Utrecht and Delft designed a material in which the curvature of the space fabric is controllable. ”We have designed an interface hosting an extremely thin layer of free electrons. It is sandwiched between strontium titanate and lanthanum aluminate, which are two insulating oxides,” says Carmine Ortix, professor at the University of Salerno and coordinator of the theoretical study. This combination allows us to obtain particular electronic geometrical configurations which can be controlled on-demand.
One atom at a time
To achieve this, the research team used an advanced system for fabricating materials on an atomic scale. Using laser pulses, each layer of atoms was stacked one after another. ”This method allowed us to create special combinations of atoms in space that affect the behavior of the material,” the researchers detail.
While the prospect of technological use is still far off, this new material opens up new avenues in the exploration of very high-speed electromagnetic signal manipulation. These results can also be used to develop new sensors. The next step for the research team will be to further observe how this material reacts to high electromagnetic frequencies to determine more precisely its potential applications. More

A new way of describing the connections in real-world systems such as food webs or social networks could lead to better methods for predicting and controlling them.
According to research published in the journal PNAS, by mathematicians at the University of Birmingham, mapping the hierarchies and also the incoherence within a system will enable us to predict the system’s strong and weak points.
Understanding how these connections work is crucial in many different ways — for example knowing how a disease will spread through a population, or whether every point in a communications network is ‘in the loop’.
Real-world systems like these are referred to as ‘directed networks’ by mathematicians because the connections usually flow in a specific direction. In food webs, for example, biomass will generally move upwards from plants, through herbivores and on towards apex predators. Networks are strongly connected if it’s possible to move around the network without ignoring the directionality.
If a network is perfectly “coherent,” with distinct trophic levels like plants, herbivores and carnivores, it can’t be strongly connected. However, most real-world systems are neither perfectly coherent nor completely incoherent, but lie somewhere in between. In a food web, for instance, this might occur because of omnivorous animals that will eat both plants and other animals.
The researchers found that it was possible to use this trophic incoherence to estimate the point at which a network becomes strongly connected. They demonstrated that the method works for any type of network, including those of neurons, people, species, metabolites, genes and words, among others.
Niall Rodgers, lead author on the paper, said: “Our approach opens up news possibilities for understanding all sorts of different networks that are regularly encountered in society. A disease outbreak, for example, could be thought of as a network connected by the spread of bacteria through a population. Understanding where you are in that network and whether the connectivity is strong or weak could be crucial to making decisions about infection control.”
Samuel Johnson, senior author on the paper, added: “This modelling approach could be used to disrupt networks as well, because the points at which connectivity becomes strong can be targeted. Neurologists, for example, might find new ways to treat epilepsy by pinpointing specific connections responsible for maintaining seizures.” More