Researchers have discovered a simple yet powerful way to protect atoms from losing information—a key challenge in developing reliable quantum technologies. By shining a single, carefully tuned laser beam on a gas of atoms, they managed to keep the atoms' internal spins synchronized, dramatically reducing the rate at which information is lost. In quantum sensors and memory systems, atoms often lose their magnetic orientation—or "spin"—when they collide with each other or the walls of their container. This phenomenon, known as spin relaxation, severely limits the performance and stability of such devices. Traditional methods to counteract it have required operating in extremely low magnetic fields and using bulky magnetic shielding. The new method sidesteps those constraints entirely. Instead of magnetically shielding the system, it uses light to subtly shift atomic energy levels, aligning the spins of the atoms and keeping them in sync, even as they move and collide. This creates a more resilient spin state that is naturally protected from decoherence. In lab experiments with warm cesium vapor, the technique reduced spin decay by a factor of ten and significantly improved magnetic sensitivity. This breakthrough demonstrates that a single beam of light can extend the coherence time of atomic spins, opening the door to more compact, accurate, and robust quantum sensors, magnetometers, and memory devices.

Adding lime to agricultural soils can remove CO₂ from the atmosphere, rather than cause CO₂ emissions, claims new research. The findings, based on over 100 years of data from the Mississippi River basin and detailed computer modelling, run counter to international guidelines on reducing agricultural emissions.