Researchers purified silicon-28 to 99.9999% for quantum computers

Signals Inbox·July 28, 2026·Quantum Computing

US national labs produced silicon-28 silane at 99.9999% purity, with the noise-causing silicon-29 isotope pushed below one part per million. The purity sounds like the headline, but the bigger move is that America can now make an ultra-clean, chip-ready quantum material that is at least 100 times less noisy than commercial supply.

Q1What actually happened?

The US Department of Energy says Oak Ridge and Pacific Northwest national laboratories produced silane containing 99.9999% silicon-28. They also pushed silicon-29, the isotope that creates magnetic noise, below one part per million. Silane matters because chipmakers use it to deposit thin silicon layers onto advanced chips and quantum devices.

Q2Why does one unwanted isotope matter?

Silicon-28 has no nuclear spin, so it gives qubits a relatively quiet place to operate. Silicon-29 does have nuclear spin. Its tiny magnetic field can disturb electron-spin qubits and make them lose quantum information. Natural silicon contains about 4.7% silicon-29. The new material cuts that down to less than 0.0001%.

Q3Is 99.9999% purity actually new?

Not by itself. NIST researchers reported silicon-28 above 99.9999% in 2014, including samples with less than one part per million of silicon-29. The new point is production and format. The DOE labs say they can preserve that extreme isotope purity while converting the material into silane, a gas that semiconductor tools can use. This is closer to supply-chain infrastructure than a one-off laboratory sample.

Q4Why is the timing important?

Because China announced its own silicon-28 breakthrough just one month earlier. China National Nuclear Corporation said it had started domestic mass production above 99.99% purity. The US result claims two extra nines and at least 100 times less isotope noise than commercial material. We do not have enough public data to compare production volumes, but the race has clearly moved from research papers into national supply chains.

Q5Does cleaner silicon mean better quantum computers?

Potentially, especially for silicon spin qubits. Less silicon-29 can mean longer coherence, giving a qubit more time to perform operations before its information falls apart. Past research found that reducing silicon-29 can sharply improve coherence. But material purity is only one problem. Quantum computers still need better control systems, connections, cooling, manufacturing yield and error correction.

Q6So what is the real signal?

The US is rebuilding a quantum-material capability it largely lost when its old isotope-separation machines shut down in 1998. The labs are not simply chasing a prettier purity number. They are trying to control the full path from raw isotope separation to a chemical feedstock that can enter semiconductor manufacturing. If that scales, silicon quantum companies get a cleaner domestic input and the US becomes less dependent on a tiny global supplier base.