Uranium ditelluride shows two kinds of superconductivity at once, Cornell team finds
Researchers at Cornell University have shown that uranium ditelluride can carry two different kinds of superconductivity at the same time. It is now the leading candidate for a material that could one day transform quantum computing. The work was published in Nature Physics on 30 October.
A superconductor carries electricity with no resistance, but only under special conditions. In uranium ditelluride, one kind of superconductivity appears in extreme cold. A second kind shows up only in very strong magnetic fields or under squeezing pressure. The two “flavours” differ in how electron pairs orbit each other.
The team, led by physicist Brad Ramshaw, redrew the material’s phase diagram, the map of where superconductivity appears as temperature, pressure and magnetic field change. Doctoral student Sahas Kamat, the paper’s first author, found earlier maps of the material under pressure clashed with thermodynamics. “The map people had in their heads… it’s not consistent with thermodynamics,” Kamat said. So the team built it again from scratch.
The experiments were extreme. Pressure of about 18,000 pounds focused on five millimetres, “like nine cars balanced on your pinky,” Kamat said. The sample was then cooled to between 2 and 1 kelvin, close to absolute zero. Pulse ultrasound measurements found a region where the two kinds overlapped and existed at the same time. They also found one kind disappeared as the temperature fell, pushed out by the other. Ramshaw said it was the first time this had been shown in an experiment.
Why it matters
Physicists have been searching for a topological superconductor, which could make quantum computers far more powerful and stable. “No one has yet convincingly demonstrated a topological superconductor, but now we know that uranium ditelluride at least has the right ingredients to make it happen,” Ramshaw said. But a working quantum computer is not near: Ramshaw said any application is several steps away, and at least one technology company has spent billions trying to engineer one without success. Among the roughly 6,000 superconductors catalogued, uranium ditelluride now stands out. “We’ve established that this is the most likely one we have,” Ramshaw said.
What happens next
The researchers will keep testing whether the two flavours can mix into a true topological superconductor, the key step not yet proven. Collaborators included researchers from the University of Maryland, the Karlsruhe Institute of Technology and the Canadian Institute for Advanced Research.
This article is for general information and education only. It is not legal or financial advice.
Sources
- https://news.cornell.edu/stories/2026/10/two-flavors-superconductivity-material-has-right-ingredients-twist (Cornell Chronicle, 30 October 2026)
- https://phys.org/news/2026-10/ute-reveals-flavors-superconductivity-extreme.html (Phys.org, 30 October 2026)
- https://dx.doi.org/10.1038/s41567-026-03504-z (Nature Physics, 30 October 2026)
