University of Houston Physicists Break 32-Year Ambient-Pressure Superconductivity Record With Pressure-Quenched Ceramic at 151 Kelvin
A team at the Texas Center for Superconductivity used a pressure-quenching technique on a mercury-based copper-oxide ceramic to achieve a transition temperature of 151 K at ambient pressure, surpassing a record that had stood since 1993.
Overview
Physicists at the University of Houston have set a new record for the highest superconducting transition temperature ever achieved at ambient pressure, reaching 151 Kelvin (approximately minus 122 degrees Celsius). The result, published March 9 in the Proceedings of the National Academy of Sciences, breaks a mark that had stood for more than three decades.
The previous record of 133 K was established in 1993 using a mercury-based copper-oxide ceramic known as Hg1223. The same compound, HgBa2Ca2Cu3O8+d, served as the starting material for the new work, but the Houston team applied an unconventional technique called pressure quenching to lock in a higher transition temperature without requiring continuous pressure.
The Pressure-Quenching Method
Pressure quenching involves subjecting the ceramic to intense pressure to push its superconducting properties to a higher threshold, then rapidly releasing that pressure while the material is cooled. The process effectively preserves the pressure-enhanced crystal structure at ambient conditions, allowing the material to retain its elevated transition temperature once the pressure is removed.
The technique is well established in other fields of materials science — it is commonly used, for instance, in the manufacture of synthetic diamonds — but this marks its first successful application to raise the ambient-pressure transition temperature of a superconductor.
“Our method shows that it is possible to retain that state without maintaining pressure,” senior author Ching-Wu Chu, founding director of the Texas Center for Superconductivity, said in a statement. Chu has been a central figure in high-temperature superconductivity research since the late 1980s.
Making Superconductors More Accessible
A significant practical advantage of the result is that the superconducting state can now be studied and characterized using standard laboratory equipment rather than specialized high-pressure apparatus. Lead author Liangzi Deng, an assistant professor of physics at Houston, noted that bringing the material to ambient pressure makes it far more accessible for scientists to use well-developed instrumentation.
The 18-degree improvement over the previous record may appear modest in absolute terms, but it represents a meaningful step in the long push toward superconductors that function at higher temperatures. Superconducting materials allow electricity to flow with zero resistance, and the closer the transition temperature rises toward everyday conditions, the more practical and cost-effective the technology becomes.
Why It Matters
Electricity transmission today loses approximately eight percent of energy to resistance in the grid. Superconductors that operate at higher temperatures could eventually eliminate those losses, with applications spanning power transmission, magnetic resonance imaging, fusion energy research, and faster electronics.
The ultimate prize in the field remains room-temperature superconductivity, which would require a transition temperature near 300 K. The Houston result narrows that gap to roughly 149 degrees, a distance that remains formidable but that researchers believe is not prohibited by any known physical law.
The research was supported by Intellectual Ventures, the Texas state government, and several private foundations.