Scientists in the US have found a hidden atomic disorder inside silicon quantum devices that could help answer the long-standing question of why some qubits fail or perform inconsistently. The researchers studied an industrially manufactured 12-qubit-class silicon quantum dot processor from Intel. The findings could lead to the development of more reliable silicon qubits and larger quantum computers. Testing silicon qubits The scientists relied on electrical spectroscopy to measure valley splitting while moving the position of a quantum dot along the silicon quantum well. Knowing where the variability originates could help semiconductor manufacturers to focus on improving the materials and fabrication processes for silicon quantum device production.