title: Spin splitting unconstrained by electron pairing: the spin-vibronic states.
abstract: Spin splitting of individual vibronic states was observed in a single molecule where all the electrons are paired, as well as a molecule with one extra electron injected. This observation was made possible by the use of a scanning tunneling microscope capable of reaching ∼800  mK in a magnetic field up to 9 T and the sharpness of the vibronic states, ∼1  meV. These conditions also led to the resolution of spectral diffusion caused by minute fluctuations at the probing location of the molecule.
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA.
authors.forename: Ungdon
authors.initials: U
authors.lastname: Ham
authors.forename: W
authors.initials: W
authors.lastname: Ho