Rydberg atoms — atoms with a highly excited electron — can form unusual types of molecular bonds. These bonds differ from the well-known ionic and covalent bonds not only by their binding mechanisms, but also by their bond lengths ranging up to several micrometers. Using ion microscope, physicists at the Universität Stuttgart have observed a new type of molecular bond between an ion and a Rydberg atom. Zuber et al. observed a new type...
