In the world of quantum physics, a "triplet superconductor" has long occupied the status of scientific legend — a material theorised to exist but never convincingly demonstrated. Now, researchers at the Norwegian University of Science and Technology (NTNU) say they have found strong evidence that it's real.
The material is an alloy of niobium and rhenium — called NbRe. In a paper published in Physical Review Letters in late 2025, Professor Jacob Linder's team at NTNU's QuSpin centre presented experimental data showing that NbRe exhibits properties consistent with triplet superconductivity — a signature that cannot be explained by conventional superconducting theory.
If confirmed, it would be a landmark discovery for quantum computing and materials science.
What Makes Triplet Superconductors Special
Conventional superconductors — the ones that power MRI machines and particle accelerators — work by pairing electrons with opposite spins. This allows them to carry electrical current with zero resistance. But the spin information — the quantum property that underlies quantum computing — is lost in the process.
A triplet superconductor works differently. Its electrons pair with aligned spins, forming what physicists call "triplet Cooper pairs." This means it can carry not only electrical current with zero resistance, but spin current too — with absolute zero energy loss.
The implications are significant:
- Quantum computers built with triplet superconductors could maintain quantum states — the qubits that store information — with far greater stability and far lower error rates
- The material could also enable the creation of Majorana particles, considered one of the most promising building blocks for fault-tolerant quantum computation
- Spintronics devices — electronics that use electron spin rather than charge — could become dramatically more energy-efficient
Why NbRe Is Promising
NbRe becomes superconducting at approximately 7 Kelvin (-266°C). While still cryogenic, this is relatively high for an exotic superconductor — many other potential candidates require temperatures closer to 1 Kelvin, making experimental work far more difficult and expensive.
The NTNU team observed inverse spin-valve effects in the material — a specific signature that is theoretically inconsistent with ordinary singlet superconductivity, but consistent with triplet pairing. NbRe's non-centrosymmetric crystal structure is also theoretically predicted to support the kind of mixed-symmetry pairing that triplet superconductivity requires.
"This is potentially a very significant discovery," Professor Linder told Science News. "We have been looking for triplet superconductors for a long time."
Caution and the Road to Confirmation
The team is careful to note that further independent verification is needed. Extraordinary claims in physics require extraordinary evidence, and a single lab's findings — however compelling — need to be replicated by other experimental groups before the physics community will fully accept them.
That process is now underway. The paper has attracted significant attention from quantum materials researchers globally, and follow-up experiments using different measurement techniques are being planned.
But the early signs are genuinely exciting. A material that can transmit quantum spin without energy loss, operate at accessible cryogenic temperatures, and potentially host Majorana particles would open new design pathways for the next generation of quantum computers — ones that are more stable, more scalable, and ultimately more powerful.
The holy grail of quantum materials may have just been found in the crystalline structure of two elements discovered in the 19th century.
Sources: Physical Review Letters (November 2025) · Norwegian University of Science and Technology QuSpin Centre · SciTechDaily · Norwegian SciTech News · EurekAlert (March 2026)
