University of Houston researchers have achieved a significant superconductivity breakthrough by setting a brand new temperature record for superconductors operating under ambient pressure conditions. The advance could eventually help create more efficient electrical grids, improved energy storage systems, faster electronics, and latest technologies for fusion energy and medical imaging.
Scientists from the Texas Center for Superconductivity (TcSUH) and the University of Houston department of physics reached a superconducting transition temperature (Tc) of 151 Kelvin (about minus 122 degrees Celsius). That’s now the best Tc ever reported for a superconductor performing at ambient pressure since superconductivity was first discovered in 1911.
The transition temperature marks the purpose where a fabric can carry electricity with zero resistance. Increasing this temperature has been considered one of the most important goals in superconductivity research because higher operating temperatures could make superconducting technologies much more practical and reasonably priced.
The findings by physicists Ching-Wu Chu and Liangzi Deng were published within the Proceedings of the National Academy of Sciences. Funding for the work got here from Mental Ventures, the state of Texas through TcSUH, and a number of other foundations.
“Transmitting electricity within the grid loses about 8% of the electricity,” said Chu, professor of physics, TcSUH founding director and the paper’s senior writer. “If we conserve that energy, that is billions of dollars of savings and it also saves us plenty of effort and reduces environmental impacts.”
Why Superconductors Matter
Superconductors are materials that allow electricity to flow without resistance. Because no energy is lost as heat, they may dramatically improve the efficiency of electrical systems. Scientists also see superconductors as critical for technologies comparable to magnetic resonance imaging (MRI), fusion reactors, quantum technologies, and ultrafast electronics.
The challenge is that the majority superconductors only work at extremely low temperatures, requiring expensive cooling systems that limit widespread use.
“Once we bring the fabric to ambient pressure, it becomes rather more accessible for scientists to make use of well-developed instrumentation to analyze it and further develop technologies for ambient condition operations,” said Deng, assistant professor of physics, principal investigator on the TcSUH and lead writer of the paper.
Recent Record Breaks A long time-Old Barrier
Researchers have spent a long time looking for superconducting materials with increasingly higher transition temperatures.
A significant milestone got here in 1987 when Chu and his collaborators discovered that a fabric often called YBCO could turn into superconducting at minus 180 degrees C, or 93 K. That discovery helped launch a worldwide race to develop high-temperature superconductors.
In 1993, scientists discovered a mercury-based copper-oxide ceramic called Hg1223 that reached superconductivity at minus 140 degrees C, or 133 K. That material held the ambient-pressure record for greater than 30 years.
The brand new University of Houston achievement pushes the record 18 degrees C higher to 151 K.
Pressure Quenching Creates Stable Superconductivity
The breakthrough relied on a process often called pressure quenching. While pressure techniques are commonly utilized in other fields, including diamond production, the strategy is comparatively latest in superconductivity research.
Researchers first subjected the fabric to extremely high pressure, which enhanced its superconducting behavior and increased its transition temperature. While still under pressure, the fabric was cooled to a fastidiously chosen temperature before the pressure was suddenly removed.
That rapid release effectively preserved the improved superconducting properties, allowing the fabric to stay stable even after returning to normal pressure conditions.
“Other researchers have shown that reaching superconductivity at room temperature under pressure is achievable,” Chu said. “Our method shows that it is feasible to retain that state without maintaining pressure.”
A Step Toward Room-Temperature Superconductors
Although room-temperature superconductivity at ambient pressure stays out of reach, researchers say the brand new record is a crucial advance toward that goal. Room temperature is roughly 300 K, leaving a niche of about 140 degrees C from the newly achieved record.
“This finding has great potential,” Chu said. “We imagine, with enough people working on it and given enough time, we should always give you the chance to comprehend the potential.”
Chu and Deng also contributed to a companion perspective paper funded by Mental Ventures and published in PNAS. The paper discusses six different approaches researchers could use to lift superconducting temperatures further, including pressure quenching.
“Room-temperature superconductivity has been seen as a ‘holy grail’ by scientists for over a century,” said Rohit Prasankumar, director of superconductivity research at Mental Ventures. “The UH team’s result shows that this goal is closer than ever before. Nonetheless, the gap between the brand new record set on this study and room temperature remains to be about 140 degrees C. Closing this gap would require concerted, intentional efforts by the broader scientific community, including materials scientists, chemists, and engineers, in addition to physicists.”