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Title: Ultrafast X-ray Auger probing of photoexcited molecular dynamics

Here, molecules can efficiently and selectively convert light energy into other degrees of freedom. Disentangling the underlying ultrafast motion of electrons and nuclei of the photoexcited molecule presents a challenge to current spectroscopic approaches. Here we explore the photoexcited dynamics of molecules by an interaction with an ultrafast X-ray pulse creating a highly localized core hole that decays via Auger emission. We discover that the Auger spectrum as a function of photoexcitation—X-ray-probe delay contains valuable information about the nuclear and electronic degrees of freedom from an element-specific point of view. For the nucleobase thymine, the oxygen Auger spectrum shifts towards high kinetic energies, resulting from a particular C–O bond stretch in the ππ* photoexcited state. A subsequent shift of the Auger spectrum towards lower kinetic energies displays the electronic relaxation of the initial photoexcited state within 200 fs. Ab-initio simulations reinforce our interpretation and indicate an electronic decay to the nπ* state.
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [5] ;  [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [2] ;  [6] ;  [7] ;  [1] ;  [2] ;  [2] ;  [8] ;  [6] ;  [1] more »;  [6] ;  [2] ;  [1] ;  [9] ;  [2] ;  [1] ;  [2] ;  [2] ;  [2] ;  [1] ;  [1] « less
  1. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)
  3. Univ. di Perugia, Perugia (Italy)
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  5. Western Michigan Univ., Kalamazoo MI (United States); Univ. of Connecticut, Storrs, CT (United States)
  6. Western Michigan Univ., Kalamazoo MI (United States)
  7. Uppsala Univ., Uppsala (Sweden); Univ. of Gothenburg, Gothenburg (Sweden)
  8. Uppsala Univ., Uppsala (Sweden)
  9. Max-Born-Institut, Berlin (Germany); UNIST, Ulsan (Republic of Korea)
Publication Date:
Report Number(s):
SLAC-PUB-16907
Journal ID: ISSN 2041-1723
Grant/Contract Number:
AC02-76SF00515
Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 5; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; PHYS; atomic and molecular physics; molecular dynamics
OSTI Identifier:
1339539