'Butterfly' molecule spotted at last, completing a 20-year quantum zoo hunt

For two decades, physicists have predicted the existence of a remarkable family of exotic molecules: giant atoms bound to ordinary atoms, with an electron so distant from its nucleus that it sculpts the pair into bizarre and diverse shapes. Reported in Physical Review Letters, the final member of this "quantum zoo" has been spotted. Led by Herwig Ott at RPTU University Kaiserslautern-Landau in Germany, a team of physicists has created and detected the "butterfly" molecule, completing a 20-year hunt for the elusive structure.