How can something remain intact when it should naturally break apart? This question has been addressed by researchers at RPTU. Their work has led to the experimental observation of an unusual quantum state in which two atoms remain bound together even though they possess enough energy to separate. The results have been published in the journal Nature Physics.

“What is remarkable is that the molecular state could decay from an energetic point of view, yet quantum interference suppresses this decay,” explains professor Artur Widera, head of the Individual Quantum Systems group at RPTU. “The wave nature of matter allows a state to remain bound even though we would normally expect it to decay.”

In simple terms, particles such as atoms do not behave solely like tiny objects. They also possess wavelike properties. When such waves overlap, they can either reinforce or cancel one another, a phenomenon physicists refer to as interference. As the new study demonstrates, it is precisely this effect that prevents two atoms from separating.