The materials have potential applications in superconducting circuits for next-generation industrial electronics.
Researchers used an advanced photon source to investigate the rare properties of this material, paving the way for more efficient computing at scale.
As industrial computing needs grow, so do the size and power consumption of the hardware needed to keep up with those needs. A potential solution to this dilemma can be found in superconducting materials, which can significantly reduce energy consumption. Imagine cooling a giant data center full of servers running almost constantly Absolute zeroallowing large-scale calculations to be performed with amazing energy efficiency.
Breakthrough in superconductivity research
Physicists at the University of Washington and the U.S. Department of Energy's Argonne National Laboratory have made a discovery that could help enable this more efficient future. Researchers have discovered a superconducting material that is uniquely sensitive to external stimuli, allowing superconducting properties to be enhanced or suppressed at will. This opens new opportunities for switchable, energy-efficient superconducting circuits. The paper was published in Advancement of science.
Superconductivity is a quantum mechanical phase of matter where an electric current can flow through a material with zero resistance. This results in optimal electronic transfer efficiency. Superconductors are used in the most powerful electromagnets for advanced technologies such as magnetic resonance imaging, particle accelerators, fusion reactors, and even sky trains. Uses of superconductors have also been found in… Quantitative statistics.
Challenges and innovations in superconductivity technologies
Today's electronics use semiconductor transistors to quickly turn electrical currents on and off, creating the diodes and zeros used in information processing. Since these currents must flow through materials with limited electrical resistance, some of the energy is wasted as heat. This is why your computer gets hotter over time. The low temperatures needed for superconductivity are typically more than 200 degrees F Below freezing point, this material is impractical for hand-held devices. However, it can be useful on an industrial level.
The research team led by Chua Sanchez from University of Washington, investigating an unusual superconducting material with exceptional tunability. This crystal consists of flat sheets of magnetic 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, with one phase usually overpowering the other.
“It's actually a very uncomfortable situation for the superconducting layers, as they are pierced by magnetic fields from the surrounding europium atoms,” Sanchez said. “This weakens superconductivity and results in limited electrical resistance.”
Advanced research techniques and results
To understand the interplay between these phases, Sanchez spent a year as a resident at one of the nation's leading X-ray light sources, the Advanced Photon Source (APS), a DOE Office of Science user facility at Argonne. While there, he received support from the Department of Energy's Science Graduate Student Research Program. Working with physicists at APS 4-ID and 6-ID beamlines, Sanchez has developed a comprehensive characterization platform capable of examining the microscopic details of complex materials.
Using a combination of X-ray techniques, Sanchez and his collaborators were able to show that applying a magnetic field to the crystal could redirect europium's magnetic field lines to run parallel to the superconducting layers. This eliminates their antagonistic effects and results in a zero-resistance state. Using electrical measurements and X-ray scattering techniques, scientists were able to confirm their ability to control the behavior of matter.
“The nature of the independent factors that control superconductivity is so fascinating that one can map out a complete way to control this effect,” said Philip Ryan of Argonne, a co-author of the paper. “This possibility raises many fascinating ideas including the ability to regulate the field sensitivity of quantum devices.”
The team then applied pressures to the crystal to obtain interesting results. They found that superconductivity could be strengthened enough to overcome magnetism even without field redirection or weakened enough that magnetic reorientation could not produce a zero-resistance state. This additional parameter allows the material's sensitivity to magnetism to be controlled and customized.
“This material is exciting because you have intense competition between multiple phases, and by applying a small pressure or magnetic field, you can promote one phase over the other to turn superconductivity on and off,” Sanchez said. “The vast majority of superconductors are not nearly as easily convertible.”
Reference: “Switchable Field-Induced Superconductivity” by Joshua J. Sanchez, Gilberto Fabres, Youngseong Choi, Jonathan M. DeStefano, Elliott Rosenberg, Yue Shi, Paul Malinowski, Yina Huang, Igor Mazin, Jung-Woo Kim, Jeon-Hao Cho, and Philip J. Ryan, November 24, 2023, Advancement of science.
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