Scientists catch antimatter “atom” acting like a wave for the first time– www.sciencedaily.com

This concept became widely known through the double-slit experiment. When electrons were fired through two narrow openings, they produced a pattern of alternating light and dark bands on a detector. This pattern revealed that each electron behaved like a wave, with its quantum wave-function passing through both slits at once and interfering with itself.

Scientists later confirmed this effect with neutrons, helium atoms, and even larger molecules, establishing matter-wave diffraction as a key principle of quantum mechanics.

However, despite these advances, this phenomenon had not been directly observed in positronium. Positronium is a short-lived, two-body system made up of an electron and a positron bound together and orbiting a shared center of mass. Because both components have equal mass, researchers have long sought to understand how such a system would behave when forming a beam and undergoing diffraction.