Scientists Observe Strange Atom Exhibiting Quantum Wave Behavior

In the mysterious world of quantum physics, particles don’t always behave the way we expect. Sometimes they act like solid objects, and other times they spread out like ripples on water. Almost 100 years ago, physicist Louis de Broglie suggested that tiny particles can act like waves. This wave-like bending and spreading, called diffraction, has since been seen in electrons, neutrons, and even whole atoms and molecules. Now, researchers at Tokyo University of Science have pushed the frontier further by showing that positronium, a fleeting atom made of an electron and its antimatter twin, the positron, also behaves like a wave. They shot a beam of positronium through a thin sheet of graphene. The particles spread out and formed interference patterns, clearly showing that this unusual atom behaves like a wave of light or a ripple in water. Professor Yasuyuki Nagashima explained the significance: “Positronium is the simplest atom composed of equal-mass constituents, and until it self-annihilates, it behaves as a neutral atom in a vacuum. Now, for the first time, we have observed quantum interference of a positronium beam, which can pave the way for new research in fundamental physics using positronium.” Antimatter research: Scientists cool Positronium to near absolute zero The breakthrough was made possible by a new way of producing high-quality positronium beams. Researchers first created positronium ions carrying an extra electron. Then, with a precisely timed laser pulse, they stripped away that electron, leaving behind a fast, neutral, and highly coherent stream of positronium atoms. Scientists aimed their adjustable positronium beam at a very thin sheet of graphene, only two or three layers thick. The spacing of atoms in the graphene matched the wave-like size of the positronium at the chosen energies. As the particles passed through, some were detected by a special sensor, which showed a clear diffraction pattern, proof that the positronium was acting like a wave. With this new method, scientists made positronium beams much stronger, reaching energies up to 3.3 keV. The beams were sharper and more precise, with less energy variation and a straight, focused path. The experiments were done in an ultra-high vacuum, which kept the graphene surface clean and made the wave-like diffraction patterns easy to see. The experiments showed that positronium acts like a single quantum particle, like an electron. Instead of behaving separately, the two parts stay together and move as one. Dr. Nagata emphasized the importance of this finding: “This groundbreaking experimental milestone marks a major advance in fundamental physics. It not only demonstrates positronium’s wave nature as a bound lepton-antilepton system (a system that behaves like a tiny atom) but also opens pathways for precision measurements involving positronium.” The implications go beyond pure physics. Because positronium carries no electric charge, it could become a powerful tool for studying delicate surfaces without damaging them. Journal Reference: