Professor Atsushi Noguchi and his team have successfully developed a planar superconducting resonator with the world’s highest level of internal Q value, a key indicator of longevity, through a unique design that combines high-quality titanium nitride thin films and a spiral shape in collaboration with RIKEN and the National Institute of Information and Communications Technology. While planar resonators excel in compactness, they have been considered disadvantaged in performance due to significant energy loss at the surface compared to three-dimensional cavity resonators. By controlling the electric field distribution with the spiral shape, they suppressed the concentration of electric fields at the surface, a main cause of energy loss, achieving an internal Q value close to 10 million at the single photon level and approximately 100 million under high power conditions, where quantum characteristics become prominent. This technology is expected to serve as a foundational technology for realizing quantum memory capable of holding quantum information for extended periods and for quantum error-correcting calculations. The resulting paper was published online in the June 13 issue of the scientific journal “EPJ Quantum Technology.”