Physicists Observe Predicted Quantum 'Bethe Strings'

University of Innsbruck physicists created and observed "Bethe strings" in an ultracold gas, fulfilling a 1931 quantum prediction by Hans Bethe. This breakthrough, published in Nature, involved cooling cesium atoms to near absolute zero and trapping them, allowing atoms to bind without chemical bonds. These stable, multi-particle clusters offer new ways to explore quantum many-body states.