The researchers repair a quantum memory by cooling its neighbour. In the University of Science and Technology of China’s experiment, the correction cycle works without repeatedly measuring an error signal and sending back instructions. Researchers working on trapped-ion memories get a demonstrated alternative to that control machinery, one that keeps the information usable longer than the system’s best unprotected qubit. [1] [2]

The Nature Physics study stores one logical qubit, a protected unit of quantum information, in several internal states of a single trapped ion. USTC’s account specifies four states and a second, helper ion. The two ions share a vibrating motion. That shared movement gives the researchers somewhere to send the disturbance before removing it. [1] [2]

USTC’s experiment principally corrects phase errors caused by magnetic-field fluctuations. Its multifrequency laser control moves the disturbed state back into the arrangement used to store the information. During that repair, it adds vibration to the ions’ shared motion. Components already in the correct arrangement remain unaffected. The repair leaves the disturbance in the movement. [2]

Cooling empties that movement of its extra energy. As the Nature Physics study explains, the researchers cool the helper ion, which also cools the motion it shares with the memory ion. The memory retains the corrected information, and the shared motion is ready to receive another disturbance. Alternating repair and cooling makes the cycle repeatable without the error measurements and feedback that conventional approaches typically require. [2] [1]

USTC reports that, under ambient laboratory noise, the corrected memory’s coherence time, the measured duration for which it preserves quantum information, reached about 42 milliseconds. It outlasted the best physical qubit in the same system. That comparison is the experiment’s break-even test: the protected arrangement must preserve information longer than the best available unprotected one. Researchers get evidence that this correction cycle earns its place in a memory. [2]

The publication dates put that advance in perspective. The team submitted its arXiv preprint on 23 April 2025; USTC dates the Nature Physics publication to 23 October 2026. This month brings journal publication of a previously public experimental result. The retrieved accounts establish those publication dates, rather than a date for the experiment. [3] [2]

The demonstrated stage is a trapped-ion memory experiment protecting one logical qubit against a particular kind of error. USTC identifies operations between multiple logical qubits, and protection during those operations, as further work. For researchers extending the scheme, the next gate is preserving the information while those protected units operate together. [2]