Researchers led by , a 91̽�� associate professor of physics and Clean Energy Institute researcher, and Philip Ryan, a physicist at the U.S. Department of Energy’s Argonne National Laboratory, have made a discovery that could enable this more efficient future. In a published Nov. 24 in Science Advances, the team reports finding a superconducting material that is uniquely sensitive to outside stimuli, enabling the superconducting properties to be enhanced or suppressed at will. This discovery could enable new opportunities for switchable, energy-efficient superconducting circuits.

Superconductivity is a mechanical phase of matter in which an electrical current can flow through a material with zero resistance. This leads to perfect electronic transport efficiency. Superconductors are used in the most powerful electromagnets for advanced technologies such as magnetic resonance imaging, particle accelerators, fusion reactors and even . Superconductors are also used in quantum computing.

Today’s electronics use semiconducting transistors to switch electric currents on and off quickly, creating the binary ones and zeroes used in information processing. Since these currents must flow through materials with finite electrical resistance, some of the energy is wasted as heat. This is why your computer heats up over time. The low temperatures needed for superconductivity — usually more than 200 degrees Fahrenheit below freezing — makes those materials impractical for hand-held devices. However, they could conceivably be useful on an industrial scale.

The research team, under the direction of — then a 91̽��doctoral student in physics and a fellow at the 91̽��Clean Energy Institute — examined an unusual superconducting material with exceptional tunability. This crystal is made of flat sheets of ferromagnetic europium atoms sandwiched between superconducting layers of iron, cobalt and arsenic atoms. Finding ferromagnetism and superconductivity together in nature is extremely rare, according to Sanchez, as one phase usually overpowers the other.

“It is actually a very uncomfortable situation for the superconducting layers, as they are pierced by the magnetic fields from the surrounding europium atoms,” said Sanchez, who is now a postdoctoral researcher at the Massachusetts Institute of Technology. “This weakens the superconductivity and results in a finite electrical resistance.”

To understand the interaction of these phases, Sanchez spent a year as a resident at one of the nation’s leading , the Advanced Photon Source, a DOE Office of Science user facility at Argonne. Working with physicists at the APS, Sanchez developed a comprehensive characterization platform capable of probing microscopic details of complex materials.

Using a combination of X-ray techniques, Sanchez and his collaborators showed that applying a magnetic field to the crystal can reorient the europium magnetic field lines to run parallel to the superconducting layers. This removes their antagonistic effects and allows a zero-resistance state to emerge. Using electrical measurements and X-ray scattering techniques, the researchers confirmed that they could control the behavior of the material.

“The nature of independent parameters controlling superconductivity is quite fascinating, as one could map out a complete method of controlling this effect,” said Ryan. “This potential posits several fascinating ideas including the ability to regulate field sensitivity for quantum devices.”

The team then applied stresses to the crystal with interesting results. They found the superconductivity could be either boosted enough to overcome the magnetism — even without re-orienting the field — or weakened enough that the magnetic reorientation could no longer produce the zero-resistance state. This additional parameter allows for the material’s sensitivity to magnetism to be controlled and customized.

“This material is exciting because you have a close competition between multiple phases, and by applying a small stress or magnetic field, you can boost one phase over the other to turn the superconductivity on and off,” said Sanchez. “The vast majority of superconductors aren’t nearly as easily switchable.”

Additional co-authors are Gilberto Fabbris, Yongseong Choi and Jong-Woo Kim with Argonne’s APS; Jonathan DeStefano, Elliott Rosenberg and Yue Shi of the 91̽��Department of Physics; Paul Malinowski, a postdoctoral researcher at Cornell University; Yina Huang of the Zhejiang University of Science and Technology in China; and Igor Mazin of George Mason University. The research was funded by the National Science Foundation, the David and Lucile Packard Foundation, the U.S. Department of Energy, the National Science Foundation of China, the Chinese Ministry of Public Security and the Air Force Office of Scientific Research.

Adapted from by Argonne National Laboratory.

, an associate professor of mechanical engineering and a data science fellow with the eScience Institute, was nominated by the Army Research Office in the Army Research Laboratory.

Brunton is a mechanical engineer whose research focuses on data-driven modeling and control of complex systems, such as studying how turbulent fluids behave. Brunton was nominated for his work on using machine learning to develop efficient models that accurately describe the complexities of fluid mechanics. These models will then be used in part for designing better aircraft and more efficient energy systems.

, an assistant professor of physics and faculty member with the Clean Energy Institute, was nominated by the Air Force Office of Scientific Research.

Chu was nominated for his research on high-temperature superconductivity and materials with unique properties emerging from the laws of quantum mechanics, the probability-based rules that govern the behavior of matter at the subatomic level. These materials could revolutionize telecommunications and other fields. Chu uses strain tuning, a method he developed, to deform the 3D crystalline structure of materials and probe them for exotic combinations of quantum-level properties for applications in the laboratory, industry and beyond.

, an assistant professor of epidemiology and faculty member at the Fred Hutchinson Cancer Research Center, was nominated by the U.S. Department of Health & Human Services.

Lindström is a genetic epidemiologist with an interest in understanding how genetics contributes to common complex diseases, such as cancer. She was nominated for her work investigating the shared genetic origin of different types of cancer, using genetic data on more than 500,000 individuals. Her research will inform future study designs and help identify global biological mechanisms that underlie cancer development and progression.

, an assistant professor of chemical engineering and faculty member with the Center on Human Development & Disability and the Molecular & Engineering Sciences Institute, was nominated by the U.S. Department of Health & Human Services.

Nance’s research focuses on developing nanotechnology-based therapeutics to treat diseases and injuries to the brain. Using a combination of tissue imaging techniques, nanotechnology approaches and data science tools, she models the conditions present in different brain microenvironments — information needed to streamline the development of more effective and more precise nanoscale therapeutics to repair and protect the core of our central nervous system.

, an associate professor of environmental and forest sciences, was nominated by the National Science Foundation.

Prugh is a wildlife ecologist whose research explores interactions among species and the response of wildlife communities to global change. Prugh was nominated for her work that looks at the effects large carnivores have on smaller carnivores, particularly as animal distributions change rapidly worldwide. As part of this project, Prugh is the impacts gray wolves have on coyotes and bobcats as wolves naturally recolonize Washington state.

, currently an assistant professor of computer science and engineering, also received a PECASE. Cheung, who was nominated by the U.S. Department of Energy, will join the faculty at the University of California, Berkeley later this summer.

In addition, , a chief engineer at the , received a PECASE. Schneider, who is also a 91̽��affiliate associate professor of electrical and computer engineering, was nominated by the U.S. Department of Energy.

The PECASE was established in 1996 to recognize the contributions that scientists and engineers have made to STEM fields, as well as education, leadership and public outreach. Participating federal departments and agencies nominate scientists for consideration. Final awards are coordinated by the Office of Science and Technology Policy within the Executive Office of the President.

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Open to scholars in eight scientific and technical fields — chemistry, computer science, economics, mathematics, molecular biology, neuroscience, ocean sciences and physics — the fellowships honor those early-career researchers whose achievements mark them as the next generation of scientific leaders.

The 126  were selected in close coordination with the research community. Candidates are nominated by their peers, and fellows are selected by independent panels of senior scholars based on each candidate’s research accomplishments, creativity and potential to become a leader in his or her field. Each fellow will receive $65,000 to apply toward research endeavors.

This year’s fellows come from 53 institutions across the United States and Canada, spanning fields from evolutionary biology to data science. The new Sloan Fellows at the 91̽��reflect this diversity, probing complex questions in robotics, quantum physics and the formation of the galaxy.

Cakmak, for example, directs the , where she studies human-robot interactions, end-user programming and assistive robotics. She aims to develop robots that can be programmed and controlled by diverse users.

“It’s about packaging robot capabilities at the right level and creating the right interface for different users,” said Cakmak.

Rather than aiming for a one-size-fits-all robot, Cakmak argues for customizing each robot to the unique needs, preferences and environments of users. Today, only expert roboticists can do that sort of customization. Cakmak aims to make robot programming accessible to a much wider audience. She believes this could be the key to mass adoption of robots and democratize “robot programming” jobs of the future.

Chu, of the ,  focuses on the synthesis and characterization of materials with unconventional electronic and magnetic ground states, such as high-temperature superconductors and topological insulators. Simply put, Chu manufactures materials and measures their properties.

“My goal is to find more materials of this kind and study their properties to find why they come out this way, or if there are additional hidden properties that people don’t know about,” said Chu.

The goal is to understand and control these emergent quantum behaviors and apply them to energy and information technology.

Majumdar, a researcher with the , is at the forefront of the interdisciplinary research that combines quantum materials and nanophotonics. His research attempts to store light in an optical resonator to study its tiniest components. Majumdar is setting out to build quantum systems using light that can mimic the interactions between electrons in many of today’s technologies. That would pave the way for new materials and optical nano-structures that could revolutionize computing. Developing these technologies, however, can be very difficult.

“Our plan is to engineer new materials and new optical nanostructures to make photons interact with each other, which is a key element for performing computation with light, be it quantum or classical computing,” said Majumdar.

Werk is a kind of galaxy historian, studying matter on atomic scales to help understand how galaxies — and the universe as a whole — evolve. By aiming giant telescopes at the night’s sky, she uses spectrographs to study atoms billions of light years away. Werk looks at the distinction between subatomic particles that exist both outside and inside galaxies. The outcome, she hopes, will help elucidate a better understanding of our own cosmic origins.

“When I look at the sky I see lots of different atomic transitions that I’m trying to piece together into a coherent picture,” said Werk.

�´Ǵǻ�’s research explores the ecology of parasites and pathogens in a changing world. She is interested in how human impacts on ecosystems affect the transmission of parasites. �´Ǵǻ�’s work has shown that disruption can alter what kinds of parasites are common and rare — increasing the abundance of some kinds of parasites and decreasing the abundance of others. The Sloan Fellowship will allow Wood and her team to look back in time at how parasite transmission changed as industrialization intensified human impacts on the oceans. She’ll accomplish this by examining parasites preserved in museum specimens — mainly fish floating perennially in ethanol — including many that are more than a century old.

“These fish are basically parasite time capsules,” said Wood.

By developing time profiles of parasite abundance, Wood will provide the world’s first glimpse of what parasite communities might have been like in a more “pristine” ocean.

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For more information, contact Jackson Holtz at the 91̽��News Office at 206-543-2580 or jjholtz@uw.edu.