Northeastern researchers have used a powerful computer model to probe a puzzling class of copper-based materials that can be turned into superconductors. Their findings offer tantalizing clues for a decades-old mystery, and a step forward for quantum computing.

The ability of a material to let electricity flow comes from the way electrons within their atoms are arranged. Depending on these arrangements, or configurations, all materials out there are either insulators or conductors of electricity.

But cuprates, a class of mysterious materials that are made from copper oxides, are famous in the scientific community for having somewhat of an identity issue that can make them both insulators and conductors.

Under normal conditions, cuprates are insulators: materials that inhibit the flow of electrons. But with tweaks to their composition, they can transform into the worlds best superconductors.

The finding of this kind of superconductivity in 1986 won its discoverers a Nobel Prize in 1987, and fascinated the scientific community with a world of possibilities for improvements to supercomputing and other crucial technologies.

But with fascination came 30 years of bewilderment: Scientists have not been able to fully decipher the arrangement of electrons that encodes for superconductivity in cuprates.

Mapping the electronic configuration of these materials is arguably one of the toughest challenges in theoretical physics, says Arun Bansil, University Distinguished Professor of physics at Northeastern. And, he says, because superconductivity is a weird phenomenon that only happens at temperatures as low as -300 F (or about as cold as it gets on Uranus), figuring out the mechanisms that make it possible in the first place could help researchers make superconductors that work at room temperature.

Now, a team of researchers that includes Bansil and Robert Markiewicz, a professor of physics at Northeastern, is presenting a new way to model these strange mechanisms that lead to superconductivity in cuprates.

In a study published in Proceedings of the National Academy of Sciences, the team accurately predicted the behavior of electrons as they move to enable superconductivity in a group of cuprates known as yttrium barium copper oxides.

In these cuprates, the study finds, superconductivity emerges from many types of electron configurations. A whopping 26 of them, to be specific.

During this transition phase, the material will in essence become some kind of a soup of different phases, Bansil says. The split personalities of these wonderful materials are being now revealed for the first time.

The physics within cuprate superconductors are intrinsically weird. Markiewicz thinks of that complexity as the classical Indian myth of the blind men and the elephant, which has been a joke for decades among theoretical physicists who study cuprates.

According to the myth, blind men meet an elephant for the first time, and try to understand what the animal is by touching it. But because each of them touches only one part of its bodythe trunk, tail, or legs, for examplethey all have a different (and limited) concept of what an elephant is.

In the beginning, we all looked [at cuprates] in different ways, Markiewicz says. But we knew that, sooner or later, the right way was going to show up.

The mechanisms behind cuprates could also help explain the puzzling physics behind other materials that turn into superconductors at extreme temperatures , Markiewicz says, and revolutionize the way they can be used to enable quantum computing and other technologies that process data at ultra-fast speeds.

Were trying to understand how they come together in the real cuprates that are used in experiments, Markiewicz says.

The challenge of modeling cuprate superconductors comes down to the weird field of quantum mechanics, which studies the behavior and movement of the tiniest bits of matterand the strange physical rules that govern everything at the scale of atoms.

In any given materialsay, the metal in your smartphoneelectrons contained within just the space of a fingertip could amount to the number one followed by 22 zeros, Bansil says. Modeling the physics of such a massive number of electrons has been extremely challenging ever since the field of quantum mechanics was born.

Bansil likes to think of this complexity as butterflies inside a jar flying fast and cleverly to avoid colliding with each other. In a conducting material, electrons also move around. And because of a combination of physical forces, they also avoid each other. Those characteristics are at the core of what makes it hard to model cuprate materials.

The problem with the cuprates is that they are at the border between being a metal and an insulator, and you need a calculation that is so good that it can systematically capture that crossover, Markiewicz says. Our new modeling can capture this behavior.

The team includes researchers from Tulane University, Lappeenranta University of Technology in Finland, and Temple University. The researchers are the first to model the electronic states in the cuprates without adding parameters by hand to their computations, which physicists have had to do in the past.

To do that, the researchers modeled the energy of atoms of yttrium barium copper oxides at their lowest levels. Doing that allows researchers to trace electrons as they excite and move around, which in turn helps describe the mechanisms supporting the critical transition into superconductivity.

That transition, known as the pseudogap phase in the material, could be described simply as a door, Bansil says. In an insulator, the structure of the material is like a closed door that lets no one through. If the door is wide openas it would be for a conductorelectrons pass through easily.

But in materials that experience this pseudogap phase, that door would be slightly open. The dynamics of what transforms that door into a really wide open door (or, superconductor) remains a mystery, but the new model captures 26 electron configurations that could do it.

With our ability to now do this first-principles-parameter-free-type of modeling, we are in a position to actually go further, and hopefully begin to understand this pseudogap phase a bit better, Bansil says.

For media inquiries, please contact Mike Woeste at m.woeste@northeastern.edu or 617-373-5718.

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Superconductor or not? They're exploring the identity crisis of this weird quantum material. - News@Northeastern

Image Courtesy: Smithsonian Magazine. Image depicts some of the skull caps excavated from Ngandong.

In development of science, what should matter the most is the findings that help the humanity, the findings that have the potential to open up new paradigms or those which change our understanding of the past or open our eyes to the future. The year 2019 also witnessed several such findings in the science world.

HUMAN HISTORY THROUGH GENETICS

Tracing human history has been achieved with the realm of genetics research as well. Year 2019 also witnessed some of the breakthroughs about human history based on analysis done on ancient DNA found on fossils and other sources.

One of such important findings has come up with a claim about the origin of modern human. What it says is that anatomically, modern humans first appeared in Southern part of Africa. A wetland that covered present day Botswana, Namibia and Zimbabwe was where the first humans lived some 200,000 years ago. Eventually, humans migrated out of this region. How was the study conducted? Researchers gathered blood samples from 200 living people in groups whose DNA is poorly known, including foragers and hunter-gatherers in Namibia and South Africa. The authors analyzed the mitochondrial DNA (mtDNA), a type of DNA inherited only from mothers, and compared it to mtDNA in databases from more than 1000 other Africans, mostly from southern Africa. Then the researchers sorted how all the samples were related to each other on a family tree. The data reveals that one mtDNA lineage in the Khoisan speakersL0is the oldest known mtDNA lineage in living people. The work also tightens the date of origin of L0 to about 200,000 years ago

Another very important and interesting finding in this field is that Homo Erectus, the closest ancestor of modern humans, marked its last presence on the island of Java, Indonesia. The team of scientists has estimated that the species existed in a place known as Ngandong near the Solo riverbased on dating of animal fossils from a bone bed where Homo Erectus skull caps and leg bones were found earlier. Scientists used to believe that Homo Erectus migrated out of Africa, into Asia, some two million years back. They also believed that the early human ancestor became extinct from the earth around 4 lakh years ago. But the new findings indicate that the species continued to exist in Ngandong even about 117,000 to 108,000 years ago.

So far, anything that is known about the Denisovans, the mysterious archaic human species, was confined to the Denisova caves in Altai Mountain in Siberia. Because the remnants of this ancient species could be discovered in the fossils of the Denisova cave only. But a recent report published in Nature about the discovery of a Denisovan jawbone in a cave in the Tibetan Plateau has revealed many interesting facts about archaic humans. The fossil has been found to be 1,60,000 years old with a powerful jaw and unusually large teeth, resembling the most primitive Neanderthals. Protein analysis of the fossil revealed that they are closer to the Siberian Denisovans.

Image Courtesy: dawn.com

QUANTUM COMPUTING AND SUPREMACY:

Image Courtesy: Quantum magazine.

Computer scientists nowadays are concentrating on going far beyond the speed that the present genre of computing can achieve. Now the principles of quantum mechanics are being tried to incorporate into the next-generation computing. There have been some advances, but the issue in this realm that has sparked controversies is Googles claim to have obtained quantum supremacy.

Sycamore, Googles 53-qubit computer has solved a problem in 200 seconds which would have taken even a supercomputer 10,000 years. In fact, it is a first step. It has shown that a quantum computer can do a functional computation and that quantum computing does indeed solve a special class of problems much faster than conventional computers.

On the other hand, IBM researchers have countered saying that Google hadnt done anything special. This clash indeed highlights the intense commercial interest in quantum computing.

NATURE, CLIMATE AND AMAZON FOREST

Image Courtesy: NASA Earth Observatory.

The man-made climate change has already reached a critical state. Climate researches have already shown how crossing the critical state would bring irreversible changes to the global climate and an accompanying disaster for humanity.

In the year 2019 also, the world has witnessed many devastations in the forms of storms, floods and wildfires.

Apart from the extreme weather events that climate change is prodding, the nature itself is in the most perilous state ever, and the reason is human-made environmental destruction.

The global report submitted by Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) reviewed some 15,000 scientific papers and also researched other sources of data on trends in biodiversity and its ability to provide people everything from food and fiber to clean water and air.

The report notes that out of 8 million known species of animals and plants, almost 1 million are under the threat of getting extinct and this includes more than 40% of amphibian species and almost a third of marine mammals.

The month of August witnessed an unprecedented wildfire in Amazon rainforest, the biggest in the world. The fire was so large-scale that the smoke covered nearby cities with dark clouds. It has been reported that Brazils National Institute for Space Research (INPE) recorded over 72,000 fires this year, which is an increase of about 80% from last year. More worrisome is the fact that more than 9,000 of these fires have taken place in the last week alone.

The fires have engulfed several large Amazon states in Northwestern Brazil. NASA, on August 11 noted that the fires were huge enough to be spotted from the space.

The main reason attributable to Amazon fires is widescale deforestation due to policy-level changes made by Bolsonaro regime. Many parts of the forest are now made open for the companies to set up business ventureseven the deeper parts of the forest. This has led to massive deforestation.

NEW DIMENSION TO THE TREATMENT OF EBOLA

Image Courtesy: UN News.

In the past, there had been no drugs that could have cured Ebola.

However, two out of four experimental trials carried out in Democratic Republic of Congo were found to be highly effective in saving patients lives. The new treatment method used a combination of existing drugs and newly developed ones. Named as PALM trial, the new method uses monoclonal antibodies and antiviral agencies.

Monoclonal antibodies are antibodies that are made by identical immune cells that are all clones of a unique parent cell. The monoclonal antibodies bind to specific cells or proteins. The objective is that this treatment will stimulate the patients immune system to attack those cells.

KILOGRAM REDEFINED

Image courtesy: phys.org

Kilogram, the unit to measure mass was defined by a hunk of metal in France. This hunk of metal, also known as the International Prototype Kilogram or Big K, is a platinum-iridium alloy having a mass of 1 kilogram housed at the Bureau of Weights and Measures in France since 1889. The IPK has many copies around the world and are used to calibrate scales to make sure that the whole world follows a standard system of measurement.

But the definition of the Kilogram will no longer be the same. On the International Metrology Day this year, the way a Kilogram has been measured for more than a century has been changed completely. Now, the kilogram would be defined using the Planck constant, something that does not change.

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Year 2019 in Science: History of Humans, Ebola Treatment and Quantum Computing - NewsClick

According to The Washington Post, the Trump administration has floated a proposal that would limit high-tech exports to China.

Under the proposal, artificial intelligence (AI), robots, quantum computing, image recognition and self-driving tech would all be prohibited from being exported to China. This would include the tech that drives smartphone assistants, such as Siri.

If you think about the range of products this potentially implicates, thats massive. This is either the opening of a big negotiation with the industry and the public or a bit of a cry for help in scoping these regulations, R. David Edelman, the director of the Project on Technology, the Economy, & National Security at MIT, told The Washington Post.

At the very least, the administration seems intent on extending the restrictions to those countries that are already subject to U.S. arms embargoes, including China.

Needless to say, industry experts are not happy with the proposal. In a separate report by The Washington Post, individuals with the National Venture Capital Association expressed concern about how effective these proposed restrictions would be, versus the damage they would cause.

Almost everything is using AI in one way or another, said Jeff Farrah, NVCAs general counsel. So then is everything subject to export controls?

Farrah continued: Theres not a lot of faith from people in the industry that the government will get this right.

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US Government Looks To Restrict Exports Of AI, Quantum Computing And Self-Driving Tech - WebProNews

Light-fidelity

LiFi (or light fidelity) will transform how machines and seafarers communicate in the future. It is 10 times faster and far more reliable than wireless fidelity (wifi).

This technology, pioneered at the University of Edinburgh, UK, uses light waves instead of radio signals to transmit information. LiFi is therefore an ideal medium for real-time and deterministic wireless data communications.

Data connections with LiFi will offer consistent quality and transmission times in the microsecond range. It is suitable for mobile applications in maritime industrial robotics and automation technology a true enabler of autonomous ship technology for the future.

Satellite grappling

Maritime communications will be boosted by highly powered low-Earth orbit (LEO) satellites providing VSAT connectivity. However, a key limiting factor to constructing and operating LEO (as well as other satellite constellations of the future) will be their decommissioning and disposal.

Space junk will be an increasingly challenging issue for the satellite industry in the coming decade because of the risk of a collision impacting communications.

A technology has emerged to remedy the situation. Altius Space Machines is developing methods for orbital rendezvous, capture, de-orbit and active debris removal. This relies on developing grappling fixtures and capture techniques.

OneWeb is building these fixtures in to its LEO satellites as it prepares to commission 30 per month over the next two years.

These same fixtures could be used for satellite servicing, in-space propellant transfer and on-orbit assembly, offering the potential to prolong the life of existing satellites and the reliability of maritime communications.

Quantum computers

Computer power is a key enabler of data analytics and simulation, so the faster the better. Supercomputers have made significant advances through the last decade. But future developments will be in quantum computing.

This technology uses qubits as tiny stores of data and a fundamental building block of quantum computers. It is already being used in financial research and will be used in data centres and cloud services.

Googles tests have shown a 53-qubit quantum computing chip calculated a task in 200 seconds compared with 10,000 years for conventional supercomputers.

That could transform artificial intelligence, analytics and simulations for design, reducing port congestion and seafarer training.

Harmonic radar

In man overboard situations, conventional radar struggles to identify the casualty. Technology has been developed by German institutes and a radar manufacturer that will improve search and recovery to save lives.

It is almost impossible to disseminate a person in the sea using radar because of the clutter from sea wave reflections disturbing the radar signal.

But the SEERAD technology boosts the signal from a person in the sea over this clutter using harmonic radar. It uses two radar antenna on a ship operating on different frequency bands and a frequency-converting transponder integrated into a lifejacket.

The benchmark for harmonic radar systems was identifying the target at 1 km with a transmission power of 1,000 W. Tests in the Baltic Sea in 2019 demonstrated SEERAD could locate a dummy with a transponder at a distance of 6 km with a transmission power of only 100 W.

Nanotechnology

The future for anti-corrosion and biofouling will involve nanotechnology. This will offer a pioneering solution to coatings to prevent the adherence of biomass. Nanostructured coatings using nanoparticulate substances could replace conventional paints.

These substances form and interact when corrosion and biofouling processes begin. They maximise the anti-adherent or repulsive capabilities of a surface, eliminating the need for biocide. Nanotechnology could also be used for fuel additives and alternative power systems in the future.

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News Content Hub - Five emerging technologies for the 2020s - Riviera Maritime Media