After 88 years, an atom's tuning note is measured 50 times more precisely

Strontium atoms are the quiet workhorses of the world's most precise clocks and a new generation of quantum computers — but to work with them, scientists first have to slow them down and hold them still with laser light tuned to exactly the right colour. The reference number for that tuning was last measured in 1938, by comparing strontium's glow with sunlight, and it was blurry by modern standards. Now a team at the Korea Research Institute of Standards and Science (KRISS) has measured it properly: after a year of careful work, using a photonic grating chip in place of vibration-prone mirrors and checking the answer two independent ways, they cut the uncertainty to about 5 megahertz — more than 50 times sharper than the 1938 value. The new figure is tied to Korea's national time standard, so any laboratory in the world can set its lasers to the same note — one small, exact number that should help quantum devices shrink and break free from bulky reference equipment.

SDG 9 · Industry, innovation and infrastructure — Mechanism: tech innovation