Isolating Attosecond Electron Dynamics in Molecules where Nuclei Move Fast

Attosecond photoionization delays in the vicinity of molecular Feshbach resonances

“…However, this complexity, which reflects in the many overlapping spectral features, may prevent one from extracting photoionization delays from real experiments. To solve this problem, current experimental efforts are pursuing to combine the RABBIT technique with alignment ( 37 ) or multicoincidence detection techniques ( 22 , 23 , 25 , 35 ) that can provide photoelectron spectra for a given molecular orientation, thus reducing the number of accessible channels. In addition, if one has access to the photoelectron angular distributions, which is now the state of the art in atomic RABBIT, the number of accessible channels can be further decreased, thus allowing for a more clear isolation of the spectral features of interest.…”

“…The presence of Feshbach resonances has been shown to have marked consequences in the determination of photoionization phases in the context of RABBIT and streaking experiments performed in the N 2 and H 2 molecules ( 22 , 34 , 35 ), where not only the energy (and eventually the ejection direction) of the electron must be measured (as in atoms), but also the vibrational state of the remaining molecular cation (nondissociative ionization) or the kinetic energy of the ionic fragments (dissociative ionization), as well as the molecular orientation with respect to the light polarization direction, must be determined. For a correct interpretation of these interferometric measurements, theoretical calculations that account for both the electronic and nuclear motions, the coupling between them, and electron correlation responsible for the autoionizing decay and the bound-continuum and continuum-continuum transitions induced by the XUV and IR pulses are mandatory.…”

“…We show that information about such resonances can be better retrieved from angularly resolved RABBIT spectra for a fixed molecular orientation (i.e., in the molecular frame). Current experimental efforts are pursuing this goal by combining RABBIT setups with multicoincidence detection methods ( 22 , 23 , 25 , 35 ) or by aligning the molecule with an auxiliary laser [see, e.g., ( 37 )].…”

Trends in angle-resolved molecular photoelectron spectroscopy

“…[447][448][449] Despite the popularity of challenging pump-probe experiments, quite few probe the dynamics beyond the simple photoelectron spectra, often leading to a limited characterization of the internal dynamics, with remaining ambiguities. The rich information embodied in angularly resolved studies from oriented molecules will be greatly beneficial to fully characterize the electronic states involved, their coupling with nuclear motion, 450 and the electron wavepacket coherences 395,451,452 and bifurcations, up to now quite elusive, both in valence excitation and ionization with broad pulses.…”

Dissociative ionization of the H2 molecule under a strong elliptically polarized laser field: carrier-envelope phase and orientation effect

“…The hydrogen molecule and its ionic companion serve as benchmark molecular systems to understand the complex strong-field processes at the fundamental level. [12][13][14][15][16][17][18][19][20] Various experimental parameters are used to control the electronic and nuclear dynamics in these simple molecular systems in real time, such as peak intensity of the laser pulse, polarization, relative phase between the two-color laser pulses, pulse duration, chirp, wavelength, etc. 12,15,21,22 In molecules, the dynamics of the nuclei follow the slower-moving pulse envelope, whereas the electrons follow the rapidly oscillating electric field under the envelope.…”