Pairs of atoms observed existing in two places at once for the first time

Quantum physicists at ANU have observed atoms entangled in motion. "It's really weird for us to think that this is how the universe works," says Dr. Sean Hodgman from the ANU Research School of Physics. "You can read about it in a textbook, but it's really weird to think that a particle can be in two places at once."

Their experiment using helium atoms represents a major advancement over similar experiments using photons, which are particles of light. Unlike photons, helium atoms are massive particles that can be held, cooled, and manipulated in gravitational fields. The research is published in Nature Communications.

"Experimentally, it's extremely hard to demonstrate this," says lead author and Ph.D. researcher, Yogesh Sridhar Arthreya. "Several people have tried in the past to show these effects, and they have always come short."

The development enables new ways to examine one of the biggest unanswered questions about the universe: How does the small-scale physics of quantum mechanics interact with gravity and general relativity at the universal scale?

"This result confirms the predictions of over a century ago that matter can be in two locations at once, and it can interfere with itself even in those locations," says Dr. Sean Hodgman.

By observing quantum entanglement in atoms for the first time, are we one small step closer to finding out whether the "theory of everything" is not just hot air?