In a city better known for sweltering summers than frozen physics, University of Houston researchers say they have set a new world record for how warm a material can be and still act like a superconductor at normal atmospheric pressure.
Physicists at UH report they have pushed the superconducting transition temperature to roughly 151 kelvin (about −122 °C) using a technique that traps a pressure‑boosted state even after that pressure is removed. The work, led by Paul Ching‑Wu Chu and Liangzi Deng at the Texas Center for Superconductivity, nudges lab‑scale superconductivity closer to conditions engineers can realistically test and, one day, deploy. The team says the advance could ultimately cut energy losses in power transmission and open new paths for electronics and fusion technologies.
The result appears in a paper published online March 9 in the Proceedings of the National Academy of Sciences, where the group reports superconductivity to 151 K in the mercury‑based cuprate HgBa2Ca2Cu3O8+δ after a pressure‑quench treatment. The paper backs the claim with resistance measurements, synchrotron X‑ray diffraction and calculations.
According to the researchers, the record came from a carefully choreographed sequence: apply extremely high pressure, cool the sample down, then suddenly release the pressure to “freeze in” the high‑pressure electronic state at ambient conditions. The approach is known as a pressure‑quench protocol. “We got very excited. We even didn't sleep that night,” Deng said, while Chu called it “that's the eureka moment” in an interview with Houston Public Media.
The Pressure‑Quench Trick
In practical terms, the team squeezed tiny samples in diamond‑anvil cells to about 10 to 30 gigapascals, cooled them close to liquid‑helium temperatures, then rapidly dropped the pressure. Done correctly, that maneuver can preserve a pressure‑enhanced superconducting phase at everyday atmospheric conditions.
It is not exactly gentle work. Chu has warned that rapid depressurization can destroy equipment, and the team reports that the boosted superconducting behavior lingered only for days in cold storage. Some outside physicists also point out that the experiments show large resistance drops but do not yet demonstrate strict zero resistance in every case, as reported by Science News.
Why It Matters For Power Grids
Superconductors allow electrical current to flow without resistance, so pushing their operating temperatures higher is the holy grail for turning exotic lab samples into grid hardware. Chu has noted that transmitting electricity typically wastes about 8 percent of generated power, and the UH team argues that higher‑temperature superconductors that work at ambient pressure could slash those losses and save serious money.
The work could be especially important in hot regions where power lines and equipment heat up just when demand spikes. That is a daily reality in places like Houston, where air conditioners and industrial loads hammer the grid every summer, according to the University of Houston.
Caveats And Next Steps
Even with the buzz, no one is wheeling out superconducting power cables for Houston’s freeways tomorrow. The experiments used a mercury‑based cuprate, scaling the method is still an open engineering headache, and the enhanced superconducting state weakened at higher storage temperatures. Independent replications, long‑term stability tests and definitive zero‑resistance measurements will all be crucial before engineers can start serious design work.
A companion perspective in the same PNAS issue outlines a broader research agenda for pushing toward room‑temperature superconductivity, as reported by ScienceMag.
For now, this is a splashy proof of principle. The UH team has shown that pressure‑induced high‑Tc states can, in some cases, be locked in at ambient pressure and studied with more conventional lab tools. Researchers emphasize that true room‑temperature superconductivity is still a long way off, but many say this result sharpens the practical roadmap for how the field might get there in the years ahead, per the PNAS.
