One of the major limitations for real-world applications of this technology is that the materials that make superconducting possible typically need to be at extremely cold temperatures to reach that level of electrical efficiency. To get around this limit, researchers need to build a clear picture of what different superconducting materials look like at the atomic scale as they transition through different states of matter to become superconductors.

Scholars in a Brown University lab, working with an international team of scientists, have moved a small step closer to cracking this mystery for a recently discovered family of superconducting Kagome metals. In a new study, they used an innovative new strategy combining nuclear magnetic resonance imaging and a quantum modeling theory to describe the microscopic structure of this superconductor at 103 degrees Kelvin, which is equivalent to about 275 degrees below 0 degrees Fahrenheit.

The researchers described the properties of this bizarre state of matter for what’s believed to be the first time in Physical Review Research. Ultimately, the findings represent a new achievement in a steady march toward superconductors that operate at higher temperatures. Superconductors that can operate at room temperature (or close to it) are considered the holy grail of condensed-matter physics because of the tremendous technological opportunities they would open in power efficiency, including in electricity transmission, transportation and quantum computing.

“If you are ever going to engineer something and make it commercial, you need to know how to control it,” said Brown physics professor Vesna Mitrovi?, who leads a condensed matter NMR group at the University and is a co-author on the new study. “How do we describe it? How do we tweak it so that we get what we want? Well, the first step in that is you need to know what the states are microscopically. You need to start to build a complete picture of it.”

The new study focuses on superconductor RbV3Sb5, which is made of the metals rubidium vanadium and antimony. The material earns its namesake because of its peculiar atomic structure, which resembles a basketweave pattern that features interconnected star-shaped triangles. Kagome materials fascinate researchers because of the insight they provide into quantum phenomena, bridging two of the most fundamental fields of physics — topological quantum physics and condensed matter physics.

Previous work from different groups established that this material goes through a cascade of different phase transitions when the temperature is lowered, forming different states of matter with different exotic properties. When this material is brought to 103 degrees Kelvin, the structure of lattice changes and the material exhibits what’s known as a charge-density wave, where the electrical charge density jumps up and down. Understanding these jumps is important for the development of theories that describe the behavior of electrons in quantum materials like superconductors.

What hadn’t been seen before in this type of Kagome metal was what the physical structure of this lattice and charge order looked like at the temperature the researchers were looking at, which is highest temperature state where the metal starts transitioning between different states of matter.

Using a new strategy combining NMR measurements and a modeling theory known as density functional theory that’s used to simulate the electrical structure and position of atoms, the team was able to describe the new structure the lattice changes into and its charge-density wave.

They showed that the structure moves from a 2x2x1 pattern with a signature Star of David pattern to a 2x2x2 pattern. This happens because the Kagome lattice inverts in on itself when the temperature gets extremely frigid. The new lattice it transitions into is made up largely of separate hexagons and triangles, the researchers showed. They also showed how this pattern connects when they take one plane of the RbV3Sb5 structure and rotate it, “gazing ” into it from a different angle.

“It’s as if this one Kagome now becomes these complicated things that split in two,” Mitrovi? said. “It stretches the lattice so that the Kagome becomes this combination of hexagons and triangles in one plane and then in the next plane over, after you rotate it half a circle, it repeats itself.”

Probing this atomic structure is a necessary step to providing a complete portrait of the exotic states of matter this superconducting material transitions into, the researchers said. They believe the findings will lead to further prodding on whether this formation and its properties can help superconductivity or if it’s something that should be suppressed to make better superconductors. The new unique technique they used will also allow the researchers to answer a whole new set of questions.

“We know what this is now and our next job is to figure out what is the relationship to other bizarre phases at low temperature — does it help, does it compete, can we control it, can we make it happen at higher temperatures, if it’s useful?” Mitrovi? said. “Next, we keep lowering the temperature and learning more.”

The experimental research was led by Jonathan Frassineti, a joint graduate student between Brown and the University of Bologna, Pietro Bonfà from the University of Parma, and two Brown students: Erick Garcia and Rong Cong. Theoretical work was led by Bonfà while all the materials were synthesized at the University of California Santa Barbara. This research included funding from the National Science Foundation.

“It is reasonable to suspect that life could have started differently — or not at all — if the early chemical characteristics of our planet were different,” says Dustin Trail, an associate professor of earth and environmental sciences at the University of Rochester.

But what was Earth like billions of years ago, and what characteristics may have helped life to form? In a paper published in Science, Trail and Thomas McCollom, a research associate at the University of Colorado Boulder, reveal key information in the quest to find out. The research has important implications not only for discovering the origins of life but also in the search for life on other planets.

“We are now at an exciting time in which humankind is searching for life on other planets and moons, as well as in other planetary systems,” Trail says. “But we still do not know how — or even when, really — life started on our own planet. Research like ours helps identify specific conditions and chemical pathways that could have supported the emergence of life, work which is certain to factor prominently into the search for life outside of our planet.”

The importance of metals in the emergence of life

Research into life and its origins typically involves a variety of disciplines including genomics, the study of genes and their functions; proteomics, the study of proteins; and an emerging field called metallomics, which explores the important role of metals in performing cellular functions. As life evolved, the need for certain metals changed, but Trail and McCollom wanted to determine what metals may have been available when microbes first appeared billions of years ago.

“When hypotheses are proposed for different origin-of-life scenarios, scientists have generally assumed all metals were available because there weren’t studies that provided geologically robust constraints on metal concentrations of fluids for the earliest times of Earth’s history,” Trail says.

To address this shortcoming, Trail and McCollom studied the composition and characteristics of fluids in the lithosphere — the outer layer of Earth that includes the crust and upper mantle — billions of years ago. These lithospheric fluids are key pathways to transport dissolved parts of rocks and minerals between Earth’s interior and hydrothermal pools in its exterior where microbial life could have formed. While researchers cannot directly measure the metals that existed billions of years ago, by determining the properties of the fluids, they can infer what metals — and the concentrations of the metals — could feasibly have been transported between Earth’s interior and exterior during the time when life emerged on the planet.

Clues in billion-year-old minerals

Billion-year-old rocks and minerals are often the only direct sources of information about Earth’s earliest history. That’s because the rocks and minerals lock in information about the composition of Earth at the time they are formed.

The researchers conducted high-pressure, high-temperature experiments and applied these results to early-Earth zircons, a robust type of mineral collected at sites in Western Australia, to determine the oxygen pressure, chlorine content, and temperature of lithospheric fluids billions of years ago. They then input this information into computer models. The models allowed them to simulate the properties of the lithospheric fluids, and, in turn, simulate which metals could have travelled through the fluids to reach hydrothermal pools at Earth’s surface.

Understanding how life originated

The researchers were surprised by what the model simulations indicated. Many origin-of-life researchers, for instance, consider copper a likely component in the chemistry that could have led to life. But Trail and McCollom did not find evidence that copper would have been abundant under the constraints in their analysis.

One metal they did test that may have been available in high concentrations was manganese. While it is rarely considered in origin-of-life scenarios, today manganese helps the body form bones and assists enzymes in breaking down carbohydrates and cholesterol.

“Our research shows that metals like manganese may function as important links between the ‘solid’ Earth and emerging biological systems at Earth’s surface,” Trail says.

Trail says the research will help scientists studying the origin of life to input more concrete data into their experiments and models.

“Experiments designed with this information in mind will result in a better understanding of how life originated.”

Such genetic experiments — typically conducted in the laboratory in animal models such as mice and zebrafish — have been a mainstay of developmental biology research for decades. Much can be learned about a gene’s function in animal studies in which a gene is missing or overexpressed, but these experiments are also expensive and time-consuming.

In contrast, the newly developed software called CellOracle — described Feb. 8 in the journal Nature — can model hundreds of genetic experiments in a matter of minutes, helping scientists identify key genes that play important roles in development but that may have been missed by older, slower techniques. CellOracle is open source, with the code and information about the software available at this link.

“The scientific community has collected enough data from animal experiments that we now can do more than observe biology happening — we can build computer models of how genes interact with each other and predict what will happen when one gene is missing,” said senior author Samantha A. Morris, PhD, an associate professor of developmental biology and of genetics. “And we can do this without any experimental intervention. Once we identify an important gene, we still need to do the lab experiments to verify the finding. But this computational method helps scientists narrow down which genes are most important.”

CellOracle, which was included in a recent technology feature in the journal Nature, is one of a number of relatively new software systems designed to model insights into cellular gene regulation. Rather than simply identify the networks, CellOracle is unique in its ability to let researchers test out what happens when a network is disrupted in a specific way.

Morris and her team harnessed the well-known developmental processes of blood cell formation in mice and humans and embryonic development in zebrafish to validate that CellOracle works properly. Their studies, in collaboration with the lab of co-author and zebrafish development expert Lilianna Solnica-Krezel, PhD, the Alan A. and Edith L. Wolff Distinguished Professor and head of the Department of Developmental Biology, also uncovered new roles for certain genes in zebrafish development that had not previously been identified.

And in a related paper online in the journal Stem Cell Reports, Morris and her colleagues used CellOracle to predict what happens when certain genes are dialed up beyond their usual expression levels.

“We found that if we dialed up two specific genes, we can transform skin cells into a type of cell that can repair damaged intestine and liver,” Morris said. “In terms of regenerative medicine, these predictive tools are valuable in modeling how we can reprogram cells into becoming the types of cells that can promote healing after injury or disease.”

According to Morris, most laboratory methods for converting stem cells into different cell types, such as blood cells or liver cells, are inefficient. Maybe 2% of the cells arrive at the desired destination. Tools like CellOracle can help scientist identify what factors should be added to the cocktail to guide more cells into the desired cell type, such as those capable repairing the gut and liver.

At present, CellOracle can model cell identity in more than 10 different species, including humans, mice, zebrafish, yeast, chickens, Guinea pigs, rats, fruit flies, roundworms, the Arabidopsis plant and two species of frog.

“We get a lot of requests to add different species,” Morris said. “We’re working on adding axolotl, which is a type of salamander. They are cool animals for studying regeneration because of their ability to regrow entire limbs and other complex organs and tissues.”

Holding back this technique — which is called liquid chromatography tandem mass spectrometry or LC-MS/MS for short — is that it often requires relatively large biological samples and a number of complicated steps that must be done by hand to prepare samples for analysis.

At Brown University, a team of biomedical engineers has been working to make this time-consuming process simpler and much more automated, a key ingredient to the technique being widely adopted by clinicians. The researchers shared their results in Scientific Reports on Monday, Feb. 6.

In the study, they present a robust new method for accurately measuring and identifying eight antidepressants most commonly prescribed to women: bupropion, citalopram, desipramine, imipramine, milnacipran, olanzapine, sertraline and vilazodone.

The method does just what the researchers hoped. It is able to identify and monitor these drugs from small biological samples — 20 microliters each, which is about the equivalent of blood taken from a prick. The method is also able to be done almost entirely by liquid-handling robots found in most clinical mass spectrometry labs.

“We designed our method and put together kits so that once the samples have been collected, they can be put in a computer program for a robotic liquid handler, and all the user essentially has to do is take off the caps, press some buttons, and it will go start to finish,” said lead author Ramisa Fariha, a Brown Ph.D. student working in a microfluidic diagnostics and biomedical engineering laboratory led by Brown professor Anubhav Tripathi.

Once the samples are ready, the user puts them through the mass spectrometer, which breaks the sample down into tiny fragments that contain tell-tale signs of the drugs they are looking for. The method’s accuracy is comparable to other LC-MS/MS-based techniques but has the advantage of a much smaller sample size and is able to be largely automated using the liquid handlers.

These innovations set up the system’s immediate potential to be widely translated to clinical settings to help monitor the impacts of drugs prescribed for patients diagnosed with depression, including women experiencing postpartum depression.

“We have made a very big step,” said Tripathi, a Brown engineering professor, the lab’s principal investigator and an author on the study. “For clinical lab adaptation, you want to reduce the error by humans. The more you automate, the more robustness you get and the more trust there is from doctors.”

Depression is a growing global crisis, and women face higher rates of diagnosis than men. The percentage of patients prescribed antidepressants has tripled over the past two decades, and clinicians find themselves at a crossroad between finding the right drug to suit a patient and monitoring the abundance of it in the body, the researchers wrote in the study.

Currently, there are no commercial products in the U.S. to help clinicians directly monitor how much these drugs are present in patients, the researchers noted. Clinicians often end up relying on more qualitative methods, like surveys, because of how obtrusive mass spectrometry methods are to patients in terms of sample size and the time-consuming nature of preparing the samples for the machine.

Tripathi and colleagues in his lab started working on this potential solution in 2021 after they were asked to evaluate a commercial European kit that uses LC-MS/MS to detect drugs in humans. The work has largely been the result of a collaboration between Brown graduate and undergraduate students who work in the lab.

The researchers, led by Fariha, decided to take a crack at designing their own kit that could be just as accurate but much simpler. They started by identifying some of the most commonly used depressants and from there worked to refine the how the LC-MS/MS technique identifies the drugs, including how much of a sample it needs and establishing a control they could run against actual samples.

After running a barrage of quality control checks, tweaking and testing different methods of measuring the samples at different conditions, the researchers took their entire process for preparing the sample and broke it down so that it could be programmed into a machine that could handle the preparation of the liquids.

The Brown researchers used a JANUS G3 Robotic Liquid Handler in their work but said that clinicians can use simpler or more advanced machines. The team detailed how they programmed their machine in a way that others can easily replicate with their own equipment.

“Every time our lab and our team publishes a paper, we go into the nitty gritty so our results can be easily replicated by others,” Fariha said.

The team also created prototype kits that can be sent to clinicians so they can implement the method in their labs. The kits include the chemicals and solvents needed along with a detailed instruction booklet that calls out what clinicians should be on the lookout for based on their own experiences and the numerous tweaks they made during quality control process.

The team — known within the lab as the clinical diagnostics and automation team — plans to work next on automation projects in oncology, such as designing a kit that could detect ovarian cancer.

The automation team has a number of undergraduates who participate — an example of how Brown students collaborate with each other and with faculty to address real-world problems. Emma Rothkopf, a senior concentrating in biomedical engineering and an author on the paper, said the experience was critical in helping her directly bridge concepts she learned in the academic setting to the lab.

“I’d find myself looking at data or doing certain steps and think, ‘Oh, my gosh, I learned this in class,'” Rothkopf said.

In addition to Fariha, Tripathi and Rothkopf, other authors on the study include Prutha S. Deshpande, Mohannad Jabrah, Adam Spooner and Oluwanifemi David Okoh. The work was supported by PerkinElmer.

Now, researchers from the Georgia Institute of Technology, in collaboration with researchers from the Massachusetts Institute of Technology (MIT), have developed a new process based on 2D materials to create LED displays with smaller and thinner pixels. Enabled by two-dimensional, materials-based layer transfer technology, the innovation promises a future of clearer and more realistic LED displays.

The team published a paper in the journal Nature in February titled, “Vertical full-colour micro-LEDs via 2D materials-based layer transfer.” Co-authors also include researchers from Sejong University in Korea, and from additional institutions in the U.S. and South Korea.

Georgia Tech-Europe Professor Abdallah Ougazzaden and research scientist Suresh Sundaram (who both also hold appointments in Georgia Tech’s School of Electrical and Computer Engineering) collaborated with researchers from MIT to turn the conventional LED manufacturing process on its head — literally. Instead of using prevailing processes based on laying red, green, and blue (RGB) LEDs side by side, which limits pixel density, the team vertically stacked freestanding, ultrathin RGB LED membranes, achieving an array density of 5,100 pixels per inch — the smallest pixel size reported to date (4 microns) and the smallest-ever stack height — all while delivering a full commercial range of colors. This ultra-small vertical stack was achieved via the technology of van der Waals epitaxy on 2D boron nitride developed at the Georgia Tech-Europe lab and the technology of remote epitaxy on graphene developed at MIT.

The study showed that the world’s thinnest and smallest pixeled displays can be enabled by an active layer separation technology using 2D materials such as graphene and boron to enable high array density micro-LEDs resulting in full-color realization of micro-LED displays.

One unique facet of the two-dimensional, material-based layer transfer (2DLT) technique is that it allows the reuse of epitaxial wafers. Reusing this costly substrate could significantly lower the cost for manufacturing smaller, thinner, and more realistic displays.

“We have now demonstrated that this advanced 2D, materials-based growth and transfer technology can surpass conventional growth and transfer technology in specific domains, such as in virtual and augmented reality displays,” said Ougazzaden, the lead researcher for the Georgia Tech team.

These advanced techniques were developed in metalorganic chemical vapor deposition (MOCVD) reactors, the key tool for LED production at the wafer scale. The 2DLT technique can be replicated on an industrial scale with high throughput yield. The technology has the potential to bring the field of virtual and augmented reality to the next level, enabling the next generation of immersive, realistic micro-LED displays.

“This emerging technology has a tremendous potential for flexible electronics and the heterogenous integration in opto-electronics, which we believe will develop new functionalities and attract industry to develop commercial products from smartphone screens to medical devices,” Ougazzaden said.