Physicists Successfully Create and Characterize Trilobite Rydberg Molecules at Ultralow Temperatures

a Sketch of a Rydberg molecule. The coordinates of the Rydberg electron (blue) and ground state atom (green) relative to the Rydberg core (red) are denoted with black arrows. The relevant spins are that of the Rydberg electron s1, the electron of the ground state atom s2 and the nuclear spin of the ground state atom I. b Sketch of a trilobite molecule. The Rydberg core and the ground state atom are shown (with exaggerated size) as red and green spheres respectively. The electronic probability density projected to 2D is indicated by the density of blue dots.