Physicists solve a quantum mystery that stumped scientists for decades

Physicists at Heidelberg University have developed a new theory that finally unites two long-standing and seemingly incompatible views of how exotic particles behave inside quantum matter. In some cases, an impurity moves through a sea of particles and forms a quasiparticle known as a Fermi polaron; in others, an extremely heavy impurity freezes in place and disrupts the entire system, destroying quasiparticles altogether. The new framework shows these are not opposing realities after all, revea...