A research team led by professors from the University of Pittsburgh Department of Physics and Astronomy has announced the discovery of a new electronic state of matter. PQI members Jeremy Levy, Patrick Irvin, David Pekker, and Roger Mong are coauthors of the paper "Pascal conductance series in ballistic one-dimensional LaAIO3/SrTiO3 channels." The research focuses on measurements in one-dimensional conducting systems where electrons are found to travel without scattering in groups of two or more at a time, rather than individually. The study was published in Science on Feb. 14. Jeremy also breaks down the scientific concepts and guides the readers through their research in the following video.
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The big brown bottle of hydrogen peroxide (H2O2) is a staple of the modern medicine cabinet, always on hand for first aid needs. Lesser known uses of hydrogen peroxide include disinfecting hospital equipment and fueling spacecraft. Yet as common and beneficial of a substance as it is, hydrogen peroxide is surprisingly hard to produce and transport. Currently, hydrogen peroxide is made through what’s known as the “anthraquinone process.” This method is energy-intense, requires large-scale production, and produces large quantities of carbon dioxide (CO2) as a byproduct. While directly reacting hydrogen and oxygen to make hydrogen peroxide would be ideal, thermodynamics prefers to form the more stable water (H2O) over hydrogen peroxide.
So the challenge becomes: does a material exist that can be used to selectively, reliably, and efficiently form hydrogen peroxide whenever and wherever it’s needed, so that transporting it isn’t necessary? A team of researchers from Carnegie Mellon University has set out to meet that difficult challenge. Associate Professors Venkat Viswanathan (mechanical engineering) and Tzahi Cohen-Karni (biomedical engineering/materials science and engineering) are leading an effort to develop a cheap, renewable, and sustainable method of creating hydrogen peroxide. The team has published a paper in ACS Catalysis on the work.
A hearty congratulations to both Prof. Susan Fullerton in Pitt Chemical Engineering and Prof. Michael Hatridge in Pitt Physics as recipients of 2020 Sloan Research Fellowships! Awarded annually since 1955, the fellowships honor scholars in the U.S. and Canada whose creativity, leadership, and independent research achievements make them some of the most promising researchers working today. Winners receive $75,000, which may be spent over a two-year term on any expense supportive of their research.
Noa Marom leads a Carnegie Mellon University team in an Argonne Early Science Project with plans to use Aurora, Argonne's exascale supercomputer, to find materials that can increase the efficiency of solar cells. They use machine learning tools extensively in their research and are working with the developers of BerkeleyGW, SISSO, and Dragonfly software to prepare to run on the Aurora system.
According to Marom, “The goal of our research is to find new materials that make photovoltaic solar cells more efficient. The quest for any new materials that can enable new technologies is challenging. The materials we are researching have unique properties that make them suitable for use in solar cells, and these properties are very rare and difficult to find out of the wide array of possible materials. We are trying to accelerate the process of material discovery through computer simulation on high-performance computers (HPC) using sophisticated quantum-mechanical simulation software and machine learning (ML) tools. We are excited that our project has been accepted as one of the projects that will run on the future Aurora supercomputer as part of the Argonne ESP program. Our multi-institution team is currently modifying algorithms and workflows so they will be able to run on Aurora.”
Sangyeop Lee, PhD, assistant professor of mechanical engineering and materials science, received a $500,000 CAREER Award from the National Science Foundation (NSF) for research that would utilize machine learning to model thermal transport in polycrystalline materials. The research seeks to create a computer model that can predict the conductive properties of a material in real life, providing guidance to engineer defects for desired thermal properties.
Congratulations Dr. Lee!
Dr. Nathan Youngblood recently co-authored an exciting paper in Science Advances with his postdoctoral advisor, Dr. Harish Bhaskaran, at the University of Oxford. The following article was provided by the University of Oxford:
The first ever integrated nanoscale device which can be programmed with either photons or electrons has been developed by scientists in Harish Bhaskaran’s Advanced Nanoscale Engineering research group at the University of Oxford. In collaboration with researchers at the universities of Münster and Exeter, scientists have created a first-of-a-kind electro-optical device which bridges the fields of optical and electronic computing. This provides an elegant solution to achieving faster and more energy efficient memories and processors.
Di Xiao and Rongchao Jin continue to be listed among the most cited researchers. Jin’s research focuses on nanochemistry, and he is well-known for developing new methodologies to create gold nanoparticles with precise numbers of atoms. Xiao’s research looks at the properties of materials in relation to quantum mechanics and how these properties can be harnessed for applications in electronic and magnetic devices.
Among five other faculty members, Chandralekha Singh was honored on Nov. 19 at the third annual Provost’s Diversity in the Curriculum awards, which recognizes faculty who have taught a modified course or revised curricula to strengthen diversity and inclusion, resulting in changes of impact.
“There’s a wealth of literature which suggests that serious engagement in diversity in the curriculum, connected with classroom and outside the classroom experiences positively affects students’ awareness and attitudes toward diversity,” said Paula Davis, assistant vice chancellor for health sciences diversity in the School of Health Sciences, in her keynote speech.
Dr. Singh was recognized for incorporating into introductory courses a new “belonging intervention,” which resulted in improved grades for all students. Using a random assignment of classrooms to enable assessment, the intervention aimed to address gender and racial gaps; it is now part of the standard curriculum in the classes in which it was introduced.
The Discipline-Based Science Education Research Center, or dB-SERC, has many excellent resources to share, learn more here and congratulations to Dr. Singh!
Turbulence in fluid mechanics has been a scientific challenge since at least the 16th century when Leonardo da Vinci sketched the chaotic movements of water flowing around obstacles in the Arno River. It is regularly described as one of the last unsolved problem of classical physics – a solution to the Navier-Stokes equation, the mathematical underpinning of turbulence, was declared a Millennium Prize Problem by MIT’s Clay Mathematics Institute in 2000. The $1 million prize remains unclaimed in 2019.
Pitt researcher Peyman Givi hopes to confront that centuries-old challenge with the power of a new generation of computing. He and a team developed an algorithm capable of using quantum computing to model turbulence at an unprecedented level of detail.
Givi, Distinguished Professor of mechanical engineering and materials science, explains the importance of turbulence. “Turbulence is central to the efficiency of fuel. Turbulence enhances mixing – more mixing creates more reactions and more reactions mean more power. No turbulence, little reaction, little power.”
The challenge of modeling turbulence is evident in the Da Vinci drawings. “We create simulations of eddies – the swirling wheels and whirls and vortices of all sizes you see in the drawings. Fluid mechanics is composed of very large differences in scales. If for example you calculate drag on an airplane wing [fluid mechanics involves both liquids and gases], the largest scale is the entire wing, the smallest scale is close to nanometers. A grid big enough to take in all the scales together won’t fit on a computer. So we simulate the largest part – I don’t need to resolve the smallest scale to model the effects. But the model is not an exact science – you are introducing art into science.”
The science may become more exact using quantum computing. Givi is co-author on a May 2019 paper in the journal Combustion Theory and Modelling – “Quantum algorithm for the computation of the reactant conversion rate in homogeneous turbulence” – presenting an algorithm for predicting the rate of reaction in simulated turbulence and exploring the potential for applications of quantum technology to fluid dynamics and combustion problems. Citing the rapid progress in the development of quantum computing hardware, the paper posits the importance of designing algorithms now that could eventually run on that hardware – “quantum algorithm with a real engineering application.”
A $1 million award from the Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy Small Business Innovation Research (SBIR) program will fund collaborative research to replace ITO with metal “microgrid” conductors to improve OLED performance. The research will be led by Paul Leu, PhD, associate professor of industrial engineering at the University of Pittsburgh’s Swanson School of Engineering, and Electroninks, a technology company in Austin, Texas.
“Electronink’s metal ink can cure at low temperatures, be printed into patterns, and has conductivity comparable to bulk metal,” says Leu. “By using a new metal patterning technique that prints the metal grid directly on glass or plastic, we can create ‘microgrid’ conductors that can outperform ITO at a lower manufacturing cost.”
Leu and Electroninks began the project in 2018, working for a year in a proof-of-concept phase to show that their metal inks could work as a replacement for ITO. “The first phase of the project was successful,” says Ziyu Zhou, lead graduate student on the project. “We were able to achieve high performance, with transparency over 90 percent and sheet resistance under 1 ohm per square.” The DOE grant funds Phase II, in which Leu’s lab and Electroninks will continue to investigate and develop the technology, process, and implementation to commercial products with its industrial partners. They will be developing and evaluating the technology for a variety of applications such as displays, lighting, touch sensors, and electromagnetic interference shielding.