Cooling positronium with lasers

Most atoms are made from positively charged protons, neutral neutrons and negatively charged electrons. Positronium is an exotic atom composed of a single negative electron and a positively charged antimatter positron. It is naturally very short-lived, but researchers have now successfully cooled and slowed down samples of positronium using carefully tuned lasers. They hope this research will help others explore exotic forms of matter, and that such research might unlock the secrets of antimatter.