$INTC Intel is one of the clear leaders in silicon spin qubits for quantum computing, and a large part of that advantage comes from its use of isotopically pure silicon-28 (Si-28).
Natural silicon contains about 4.7% of the isotope Si-29, which has a nuclear spin. That nuclear spin creates magnetic noise that rapidly dephases electron spins and shortens coherence times. By using highly enriched Si-28 (typically >99.9% or better), Intel removes most of that noise source. The result is substantially longer coherence times for the electron spin qubits that form the basis of their devices.
Intel has demonstrated this approach at industrial scale. Their Tunnel Falls research chip is a 12-quantum-dot linear array fabricated on a full 300 mm CMOS production line using immersion and EUV lithography along with standard high-volume manufacturing process control. Devices built with isotopically purified Si-28 quantum wells have shown the expected improvement in coherence relative to natural-abundance silicon. Intel has distributed Tunnel Falls chips to external research groups and continues to publish progress on higher-fidelity single- and multi-qubit operations, including exchange-only encodings and early error-detection experiments.
The same material has a second, potentially more near-term benefit for classical logic. Isotopically pure Si-28 has higher thermal conductivity than natural silicon because the removal of heavier isotopes reduces phonon scattering. In bulk crystals the room-temperature improvement is modest (roughly 8–10%), but in nanowires the effect is much larger — experimental work has shown thermal conductivity gains of up to ~150% relative to natural-silicon nanowires of similar diameter and surface roughness. At advanced nodes where features are already in the nanowire regime (RibbonFET and similar gate-all-around structures), better heat extraction can translate into higher sustainable frequency, lower thermal throttling, or improved reliability.
$ASPI ASP Isotopes is currently one of the few companies scaling commercial production of highly enriched Si-28. The company has restarted the first stages of its Pretoria enrichment facility after engineering upgrades, has multiple contracts with U.S. customers for quantum-computing and semiconductor applications, and expects initial commercial shipments in the second half of 2026. ASP Isotopes markets the material both for spin-qubit substrates (where isotopic purity directly improves coherence) and for advanced logic thermal management.
There is industry speculation that Intel is among the customers evaluating or sampling the material, and that the company has brought in process expertise with prior Intel 18A experience. Public confirmation of a formal supply agreement or of Si-28 being inserted into high-volume 18A/18A-P flows is still limited. If the material is successfully integrated into the quantum-well or channel regions of RibbonFET transistors, or used in thermally critical layers, it would represent a materials-level enhancement on top of the architectural advantages of PowerVia and gate-all-around.
Most discussions of Intel’s process recovery focus on transistor architecture (RibbonFET), backside power (PowerVia), and packaging (EMIB/EMIB-T). An ability to insert isotopically engineered silicon adds a materials-science lever that few other logic foundries currently emphasize. For quantum, it keeps Intel on one of the more scalable qubit platforms because the devices can be made on the same 300 mm tooling used for classical CMOS. For classical AI/HPC chips, even a modest improvement in thermal conductivity at the device level can compound with PowerVia’s already improved power delivery and heat extraction.
Execution risk remains high. Producing and integrating high-purity Si-28 at the volumes and cost points required for leading-edge logic is non-trivial, and the thermal benefits in real product silicon still need to be demonstrated at scale. The quantum program is still research-scale. Nevertheless, the combination of a demonstrated industrial spin-qubit platform, a commercial supplier of enriched Si-28, and Intel’s existing process and packaging roadmap creates a coherent materials-to-system story that is relatively unique among the major logic players.