Canadian laser breakthrough towards laser-cooling of antimatter:
In Nature (2018), the ALPHA collaboration reports the first-ever observation of a key atomic transition in antihydrogen, the so-called Lyman-alpha transition. In ordinary hydrogen, this is one of the most important transitions in the Universe, responsible for first light produced after the Big Bang when the electrons and the protons combined to form hydrogen atoms. However, the transition is notoriously difficult to observe in antimatter, partly because of the technical challenges with producing laser light to drive the transition. The observation of the Lyman-alpha transition in antihydrogen was made possible by the development of an innovative laser system by a team from TRIUMF and the University of British Columbia. The Lyman-alpha transition not only provides important information of the structure of the anti-atom, but also can be used to control the motion of antihydrogen. In particular, the laser cooling of antihydrogen will enable the creation of ultra-cold antihydrogen, essential for future spectroscopy and the gravity studies of antimatter.