Experimental confirmation of quantum monodromy: the millimeter wave spectrum of cyanogen isothiocyanate NCNCS

Phys Rev Lett. 2005 Dec 9;95(24):243002. doi: 10.1103/PhysRevLett.95.243002. Epub 2005 Dec 5.

Abstract

We have made energy-momentum maps for the experimental end-over-end rotational energy and the two-dimensional bending vibrational energy, both of which confirm the dominating effects of nontrivial quantum monodromy in cyanogen isothiocyanate. Accidental resonances in the rotational spectra yield accurate intervals between bending states.