Zinc oxide spin qubit discovery advances scalable quantum devices
This digest was compiled by AI from multiple sources — links to the originals are below.
A research team led by Sungkyunkwan University professor Hosung Seo has identified an atomic defect in zinc oxide that functions as a spin qubit, a core component for quantum computers. The defect emits bright visible light and retains quantum information for about 4 milliseconds, enabling single-shot readout. The findings, published in PRX Quantum, offer a semiconductor-compatible alternative to diamond-based qubits.
The Defect Discovery
The team designed a molybdenum-oxygen-vacancy complex, where a molybdenum atom replaces a zinc atom next to a missing oxygen atom. Using first-principles quantum simulations, they screened candidate defects and identified this structure as a promising spin qubit. The defect emits sharp visible light with a Huang-Rhys factor far smaller than previously known zinc oxide defects, indicating high optical quality.
Quantum Performance
The electron spin at the defect retains quantum information for about 4 milliseconds even under magnetic noise. Strong spin-orbit coupling and a stable symmetric structure enable high-fidelity single-shot readout, essential for quantum error correction. The team demonstrated this theoretically, marking the first robust deep-level spin qubit in zinc oxide.
Semiconductor Advantage
Zinc oxide is widely used in the semiconductor industry and can be grown as ultrahigh-purity crystals. Unlike diamond, it is compatible with standard fabrication processes, potentially easing integration and mass production of quantum devices. The material is also 'magnetically quiet' with almost no nuclear spins, reducing decoherence.
What's Next
The team plans to experimentally realize the proposed qubit in zinc oxide samples. It remains unclear whether the defect can be reliably created and controlled at scale for practical quantum computing.
1 source
Zinc oxide spin qubit discovery advances scalable quantum devices
