Nearly a century after Nobel laureate Hans Bethe predicted their existence, scientists have created and observed unusual quantum structures known as "Bethe strings" using ultracold atoms. The experiment, led by quantum physicist Hanns-Christoph Nägerl, provides researchers with a highly controllable way to explore these unusual quantum many-body states.
In 1931, physicist Hans Bethe proposed that particles in certain quantum systems restricted to one dimension could join together into collective states now called Bethe strings. These structures differ fundamentally from familiar molecules. Rather than being connected through chemical bonds, the particles remain bound because of their interactions with one another, and the resulting states can exist only in one dimension.
For much of the past century, Bethe strings were primarily a theoretical idea. Researchers at the University of Innsbruck have now created and detected these multiparticle bound states in an ultracold gas, working with theory teams from the Department of Experimental Physics at the University of Amsterdam and the Technical University of Munich. The results were published in Nature Communications.
To read more, click here.