Quantum Scientists Put Thousands of Metal Atoms in Multiple Places Simultaneously
Researchers achieved a record-breaking quantum experiment showing that sodium nanoparticles can exist in superposition states despite containing thousands of atoms.
Physicists have achieved a mind-bending quantum experiment that pushes the boundaries of what objects can exhibit quantum behavior, demonstrating that metallic nanoparticles containing thousands of atoms can exist in multiple places at once. The groundbreaking research, published in Nature by teams from the University of Vienna and University of Duisburg-Essen, represents one of the strongest tests yet of quantum mechanics at scales approaching the macroscopic world.
The experiment involved sodium clusters measuring roughly 8 nanometers across, similar in scale to modern transistor components, with each particle containing between 5,000 and 10,000 atoms and weighing more than 170,000 atomic mass units. This makes them significantly larger and heavier than the particles typically used in quantum interference experiments, yet they still displayed clear quantum behavior by producing measurable interference patterns.
"Intuitively, one would expect such a large lump of metal to behave like a classical particle," explains lead author Sebastian Pedalino, a doctoral student at the University of Vienna. "The fact that it still interferes shows that quantum mechanics is valid even on this scale and does not require alternative models." The researchers created what they describe as "Schrödinger's metal lump," referencing the famous thought experiment about quantum superposition.
To achieve this remarkable feat, the team created ultracold sodium clusters and guided them through three diffraction gratings generated by ultraviolet laser beams. The first laser established each cluster's position with 10-nanometer accuracy while placing the particles into quantum superposition, allowing them to follow multiple paths simultaneously through the experimental apparatus. When these overlapping paths produced interference patterns, it confirmed that the particles' quantum states had spread over regions dozens of times larger than the particles themselves.
The results have profound implications for our understanding of where quantum mechanics transitions to classical physics. The experiment suggests that even surprisingly large objects continue to obey quantum rules, challenging traditional assumptions about the boundary between the quantum and classical worlds. This research could eventually lead to new quantum technologies and help scientists better understand fundamental questions about the nature of reality at different scales.