A research team led by Professor Hosung Seo of Sungkyunkwan University (SKKU) has identified the first atomic defect structure in zinc oxide (ZnO) semiconductors to function as a spin qubit. Published in PRX Quantum on June 3, 2026, the discovery offers a scalable alternative to diamond-based quantum hardware for computing and sensing.
The quest for a viable quantum computer relies on finding stable qubits—the basic building blocks of quantum information. While nitrogen-vacancy (NV) centers in diamond have long been the primary candidate, diamond is notoriously difficult to grow in large, high-quality crystals and does not align well with standard semiconductor fabrication. This has created a significant bottleneck for the mass production of quantum devices.
Because ZnO is already a staple of the semiconductor industry with well-understood physical properties, it provides a more practical path toward integration.
The Molybdenum–Oxygen-Vacancy Complex
Using supercomputer-driven first-principles quantum simulations, the researchers screened candidate defects across the periodic table to design a specific molybdenum–oxygen-vacancy complex. In this structure, a molybdenum (Mo) atom replaces a zinc (Zn) atom adjacent to a missing oxygen atom.
The team found that this specific defect emits bright, sharp light in the visible range. Crucially, the defect’s Huang-Rhys factor—which measures energy leakage into crystal vibrations—is significantly lower than in previously known zinc oxide defects. This efficiency allows for the sharp emission required for quantum light sources.
“This work is the first to show that a robust, deep-level spin qubit is feasible in zinc oxide, a representative oxide semiconductor. Combined with mature oxide-semiconductor growth and fabrication technologies, it could develop into an integrated, scalable platform for quantum light sources, quantum sensors, and quantum networks.”
Professor Hosung Seo, SKKU
Stability and Single-Shot Readout
A qubit is only useful if it can hold information long enough to perform a calculation. The SKKU team demonstrated that the electron spin in this ZnO defect can stably retain quantum information for about 4 milliseconds, even when surrounded by magnetic noise.
This stability, paired with a symmetric structure and strong spin-orbit coupling, enables single-shot readout
. This is the ability to accurately determine a spin state in one single measurement, a capability that is essential for quantum networks and quantum error correction.
Parallel Approaches to Qubit Control
While the SKKU team focuses on oxide semiconductors, other industry players are attacking the “noise” problem from different angles. MicroCloud Hologram Inc. recently reported the use of a fast adiabatic driving protocol to control two heavy hole spin qubits in a double quantum dot (QD) system. This method aims to treat charge noise as an invisible interference factor
by creating an electromagnetic shielding barrier
to keep qubits stable.
The contrast in these two approaches highlights a broader industry trend: the move away from exotic materials like diamond toward semiconductor-native solutions. Whether through the atomic defects found by SKKU or the adiabatic driving protocols used by MicroCloud Hologram, the goal is to move quantum technology out of the laboratory and into existing fabrication pipelines.
The EU’s SPINS Pilot Line and Industrial Scaling
The gap between laboratory discovery and a manufacturable processor is the primary target of the European Union’s new SPINS (Semiconductor Pilot line for Industrial Quantum NanoSystems) project. Coordinated by imec and funded with €50 million, SPINS is one of six EU pilot lines designed to move quantum chips from the lab to the fab.
The SPINS consortium, which includes 25 partners such as Fraunhofer and Infineon, is focusing on three technology platforms: Si/SiGe, Ge/GeSi, and SOI. The project intends to lower entry barriers for SMEs by providing standardized quantum process design kits (PDKs) and multi-project wafers (MPW).
“Scaling qubits requires an extremely controllable environment and solid manufacturing processing, in view of the extreme sensitivity of qubits to environmental noise.”
Kristiaan De Greve, coordinator SPINS
The next critical phase will be the transition of these theoretical and laboratory-scale defects into the standardized PDKs and 300mm wafer processes currently being developed in Europe.
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