Open AccessProbing Rydberg-Rydberg interactions in N2 by ultrafast EUV-NIR photoelectron spectroscopy
Author(s) -
Mizuho Fushitani,
Y. Toida,
François Légaré,
Akiyoshi Hishikawa
Publication year - 2019
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.019702
Subject(s) - rydberg formula , atomic physics , excited state , x ray photoelectron spectroscopy , femtosecond , spectroscopy , ultrashort pulse , population , ionization , rydberg state , materials science , photoemission spectroscopy , laser , physics , ion , optics , nuclear magnetic resonance , demography , quantum mechanics , sociology
The ultrafast dynamics of molecular nitrogen (N 2 ) just below the ionization threshold has been investigated by time-resolved photoelectron spectroscopy using a single harmonic centered at hν = 15.38 eV. The evolution of the Rydberg wavepacket launched by the ultrashort EUV pulse is probed by a time-delayed femtosecond NIR laser pulse. The observed photoelectron spectra show two series of vibrational peaks to the ground X 2 Σg+ state and the first excited A 2 Πu state of N2+. Among these, two photoelectron peaks with the vibrational quantum numbers v X+ = 4 and v A+ = 1 exhibit clear anti-phase oscillation with a period of 300 fs, showing that two Rydberg states converging to the X 2 Σg+ and A 2 Πu ionic states interact with each other, thus causing periodic switching in the population of the ion core states.