Google scientists said Wednesday they have passed a major milestone in their quest to develop effective quantum computing, with a new study showing they reduced the rate of errors—long an obstacle for the much-hyped technology.

Quantum computing has been touted as a revolutionary advance that uses our growing scientific understanding of the subatomic world to create a machine with powers far beyond those of today’s conventional computers.

However the technology remains largely theoretical, with many thorny problems still standing in the way—including stubbornly high error rates.