Mode-Specific Vibrational Autodetachment Following Excitation of Electronic Resonances by Electrons and Photons

Scientific Highlights
Reported by:  Juraj Fedor
Cate S. Anstöter, Golda Mensa-Bonsu, Pamir Nag, Miloš Ranković, Ragesh Kumar T. P., Anton N. Boichenko, Anastasia V. Bochenkova, Juraj Fedor, Jan R. R. Verlet, “Mode-Specific Vibrational Autodetachment Following Excitation of Electronic Resonances by Electrons and Photons” Physical Review Letters, vol. 124, iss. 203401 (2020).
[Bibtex] 

@article{
	author = {Cate S. Anstöter, Golda Mensa-Bonsu, Pamir Nag, Miloš Ranković, Ragesh Kumar T. P., Anton N. Boichenko, Anastasia V. Bochenkova, Juraj Fedor, Jan R. R. Verlet},
	title = {Mode-Specific Vibrational Autodetachment Following Excitation of Electronic
Resonances by Electrons and Photons},
	journal = {Physical Review Letters},
	volume = {124},
	number = {203401},
	abstract = {Electronic resonances commonly decay via internal conversion to vibrationally hot anions and subsequent statistical electron emission. We observed vibrational structure in such an emission from the nitrobenzene anion, in both the 2D electron energy loss and 2D photoelectron spectroscopy of the neutral and anion, respectively. The emission peaks could be correlated with calculated nonadiabatic coupling elements for vibrational modes to the electronic continuum from a nonvalence dipole-bound state. This autodetachment mechanism via a dipole-bound state is likely to be a common feature in both electron and photoelectron spectroscopies.},
	year = {2020},
	type= {Article},
}

Electronic resonances (temporary negative ions) commonly decay via internal conversion to vibrationally hot anions and subsequent statistical electron emission. Such emission results in a thermal electron distribution. We probed electron emission from nitrobenzene resonant anions prepared by two very different methods: either by electron collision with the neutral or by photoexcitation from the bound anion. In both cases, two-dimensional electron spectra were recorded, and, in both cases, a vibrational structure was observed on top of the thermal emission. We ascribe these to the electron emission via non-valence dipole-bound state which leads to de-excitation of specific vibrational modes. This autodetachment mechanism via a dipole-bound state is likely to be a common feature in both electron and photoelectron spectroscopies.