The outcomes and timescales of molecular nonadiabatic dynamics are decisively impacted by the quantum coherences generated at localized molecular regions. In time-resolved X-ray diffraction imaging, these coherences create distinct signatures via inelastic photon scattering, but they are buried under much stronger background elastic features. Here, we exploit the rich dynamical information encoded in the inelastic patterns, which we reveal by frequency-dispersed covariance ultrafast powder X-ray diffraction of stochastic X-ray free-electron laser pulses. This is demonstrated for the photoisomerization of azobenzene involving the passage through a conical intersection, where the nuclear wave packet branches and explores different quantum pathways. Snapshots of the coherence dynamics are obtained at high frequency shifts, not accessible with conventional diffraction measurements. These provide access to the timing and to the confined spatial distribution of the valence electrons directly involved in the conical intersection passage. This study can be extended to full threedimensional imaging of conical intersections with ultrafast X-ray and electron diffraction.

Unveiling the spatial distribution of molecular coherences at conical intersections by covariance X-ray diffraction signals / Cavaletto S.M.; Keefer D.; Rouxel J.R.; Aleotti F.; Segatta F.; Garavelli M.; Mukamel S.. - In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - ISSN 0027-8424. - STAMPA. - 118:22(2021), pp. e2105046118.1-e2105046118.8. [10.1073/pnas.2105046118]

Unveiling the spatial distribution of molecular coherences at conical intersections by covariance X-ray diffraction signals

Aleotti F.;Segatta F.;Garavelli M.;
2021

Abstract

The outcomes and timescales of molecular nonadiabatic dynamics are decisively impacted by the quantum coherences generated at localized molecular regions. In time-resolved X-ray diffraction imaging, these coherences create distinct signatures via inelastic photon scattering, but they are buried under much stronger background elastic features. Here, we exploit the rich dynamical information encoded in the inelastic patterns, which we reveal by frequency-dispersed covariance ultrafast powder X-ray diffraction of stochastic X-ray free-electron laser pulses. This is demonstrated for the photoisomerization of azobenzene involving the passage through a conical intersection, where the nuclear wave packet branches and explores different quantum pathways. Snapshots of the coherence dynamics are obtained at high frequency shifts, not accessible with conventional diffraction measurements. These provide access to the timing and to the confined spatial distribution of the valence electrons directly involved in the conical intersection passage. This study can be extended to full threedimensional imaging of conical intersections with ultrafast X-ray and electron diffraction.
2021
Unveiling the spatial distribution of molecular coherences at conical intersections by covariance X-ray diffraction signals / Cavaletto S.M.; Keefer D.; Rouxel J.R.; Aleotti F.; Segatta F.; Garavelli M.; Mukamel S.. - In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - ISSN 0027-8424. - STAMPA. - 118:22(2021), pp. e2105046118.1-e2105046118.8. [10.1073/pnas.2105046118]
Cavaletto S.M.; Keefer D.; Rouxel J.R.; Aleotti F.; Segatta F.; Garavelli M.; Mukamel S.
File in questo prodotto:
File Dimensione Formato  
Time_Freq_Diffraction5.pdf

Open Access dal 29/11/2021

Tipo: Postprint
Licenza: Licenza per Accesso Aperto. Creative Commons Attribuzione - Non commerciale - Non opere derivate (CCBYNCND)
Dimensione 3.86 MB
Formato Adobe PDF
3.86 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/845937
Citazioni
  • ???jsp.display-item.citation.pmc??? 5
  • Scopus 13
  • ???jsp.display-item.citation.isi??? 15
social impact