We present an experimental and theoretical energy- and angle-resolved study on the photoionization dynamics of non-resonant one-color two-photon single valence ionization of neutral N$$_2$$ molecules. Using 9.3 eV photons produced via high harmonic generation and a 3-D momentum imaging spectrometer, we detect the photoelectrons and ions produced from one-color two-photon ionization in coincidence. Photoionization of N$$_2$$ populates the X $$^2\Sigma^+_g$$, A $$^2\Pi_u$$, and B $$^2\Sigma^+_u$$ ionic states of N$$_2^+$$, where the photoelectron angular distributions associated with the X $$^2\Sigma^+_g$$ and A $$^2\Pi_u$$ states both vary with changes in photoelectron kinetic energy of only a few hundred meV. We attribute the rapid evolution in the photoelectron angular distributions to the excitation and decay of dipole-forbidden autoionizing resonances that belong to series of different symmetries, all of which are members of the Hopfield series, and compete with the direct two-photon single ionization.
Larsen, Kirk A., et al. "Role of dipole-forbidden autoionizing resonances in nonresonant one-color two-photon single ionization of N<sub>2</sub>." Physical Review A, vol. 102, no. 6, Dec. 2020. https://doi.org/10.1103/physreva.102.063118
Larsen, Kirk A., Bello, Roger Y., Lucchese, Robert R., Rescigno, Thomas N., McCurdy, C. William, Slaughter, Daniel S., & Weber, Thorsten (2020). Role of dipole-forbidden autoionizing resonances in nonresonant one-color two-photon single ionization of N<sub>2</sub>. Physical Review A, 102(6). https://doi.org/10.1103/physreva.102.063118
Larsen, Kirk A., Bello, Roger Y., Lucchese, Robert R., et al., "Role of dipole-forbidden autoionizing resonances in nonresonant one-color two-photon single ionization of N<sub>2</sub>," Physical Review A 102, no. 6 (2020), https://doi.org/10.1103/physreva.102.063118
@article{osti_1670144,
author = {Larsen, Kirk A. and Bello, Roger Y. and Lucchese, Robert R. and Rescigno, Thomas N. and McCurdy, C. William and Slaughter, Daniel S. and Weber, Thorsten},
title = {Role of dipole-forbidden autoionizing resonances in nonresonant one-color two-photon single ionization of N<sub>2</sub>},
annote = {We present an experimental and theoretical energy- and angle-resolved study on the photoionization dynamics of non-resonant one-color two-photon single valence ionization of neutral N$_2$ molecules. Using 9.3 eV photons produced via high harmonic generation and a 3-D momentum imaging spectrometer, we detect the photoelectrons and ions produced from one-color two-photon ionization in coincidence. Photoionization of N$_2$ populates the X $^2\Sigma^+_g$, A $^2\Pi_u$, and B $^2\Sigma^+_u$ ionic states of N$_2^+$, where the photoelectron angular distributions associated with the X $^2\Sigma^+_g$ and A $^2\Pi_u$ states both vary with changes in photoelectron kinetic energy of only a few hundred meV. We attribute the rapid evolution in the photoelectron angular distributions to the excitation and decay of dipole-forbidden autoionizing resonances that belong to series of different symmetries, all of which are members of the Hopfield series, and compete with the direct two-photon single ionization.},
doi = {10.1103/physreva.102.063118},
url = {https://www.osti.gov/biblio/1670144},
journal = {Physical Review A},
issn = {ISSN 2469-9926},
number = {6},
volume = {102},
place = {United States},
publisher = {American Physical Society (APS)},
year = {2020},
month = {12}}