A research team from the UK's National Physical Laboratory (NPL), in collaboration with Chalmers University of Technology and Royal Holloway, University of London, has published a breakthrough achievement in Science Advances, successfully imaging a single two-level system (TLS) defect in a superconducting quantum circuit for the first time. This research provides a new technical approach for improving the stability of quantum computers.

One of the core challenges facing quantum computers is quantum-state decoherence, and TLS defects in superconducting circuits are a major contributing factor. The research team developed a novel instrument combining advanced microscopy with real-time quantum circuit monitoring. In an environment close to absolute zero, they successfully captured the influence of an individual TLS defect on the quantum circuit. NPL Senior Scientist Dr. Riju Banerjee described: "The observed data shows ring-shaped patterns resembling ripples on a pond, vividly illustrating the interaction between the defect and the circuit."

The study marks the first time such microscopic defects have been identified at a chemical level, laying the foundation for their eventual removal. NPL Principal Scientist Dr. Sebastian de Graaf stated: "This tool will help us gain deeper insights into the properties of defects that affect quantum circuits." Researchers believe that by locating and eliminating TLS defects, the stability and reliability of quantum computers can be significantly improved.

This technological breakthrough holds great significance for advancing practical quantum computing. In the future, more stable quantum computers will play key roles in fields such as cryptography, drug discovery, and energy optimization. The research team plans to further refine the technology to enable even more precise characterization and effective control of such defects.