SKKU-led Team Identifies ‘Zinc Oxide Spin Qubit’ — A Semiconductor-Based Quantum Technology

Researchers at Sungkyunkwan University, in collaboration with the University of Wisconsin-Madison and the University of Washington, have identified a new method to advance quantum computing. By focusing on a molybdenum-oxygen-vacancy defect within zinc oxide, the team has proposed a new spin qubit structure that functions as a fundamental building block for future quantum hardware.

Traditional quantum platforms, such as diamond-based systems, present significant challenges for mass production due to difficulties in crystal growth and integration with standard semiconductor fabrication. Zinc oxide offers a distinct advantage because the semiconductor industry already maintains established growth and fabrication processes for this material. The team utilized first-principles quantum simulations to screen candidate defects and determined that this specific molybdenum complex provides necessary properties for quantum operations.

Key performance metrics for this proposed qubit include high-efficiency visible-light emission and a low Huang-Rhys factor. These features suggest that the defect can serve as an efficient quantum light source. The study also indicates a spin coherence time of approximately 4 milliseconds. This duration allows for high-fidelity single-shot spin readout, which is a requirement for reliable quantum error correction and network stability.

Professor Hosung Seo of SKKU emphasized that this finding marks the first demonstration of a viable spin qubit within a common oxide semiconductor. Because zinc oxide is magnetically quiet and supports high-purity crystal growth, it provides a stable environment for quantum information. This research, recently published in PRX Quantum, creates a path toward developing scalable platforms for sensors, communications, and computing applications that are compatible with existing industrial semiconductor technology.