Nonequilibrium dynamics of the many-body electronic excitations in atomic, molecular and model systems

• Applicant: Dr. Yaroslav Pavlyukh
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 231449284

• Final Report Year: 2017

Final Report Abstract

The goal of this project was to develop the NEGF class of methods to describe the dynamics of electronic excitations in atomic, molecular and model systems far from equilibrium and to use these methods to study the light-matter interaction on the attosecond timescale and electron transport on the nanoscale. We were motivated by the emergence of attosecond physics, molecular electronics and tunneling spectroscopy with atomic resolution. The work on the project fulfilled all our original expectations concerning the consistent description of both neutral and charged excitations, inclusion of electronic correlations on a very high level, addressing realistic systems and a variety of excited state relaxation mechanisms. Our major works have been published in the collaboration with experimentators or in the direct comparison with most advanced experiments. Excellent agreement between theory and experiment have been found in all the cases. Also, proposals for new investigations have been made. On the more fundamental side, our works on the convergence properties of many-body perturbation theories and on the positive definite diagrammatic approximations involve international collaborations, are solving long-standing problems in condensed matter physics, and are of general interest.

Publications

• Nuclear-wave-packet dynamics mapped out by twocenter interference in the HeH molecule, Phys. Rev. A 89, 063421 (2014)
  M. Schüler, Y. Pavlyukh, and J. Berakdar
  
• Disentangling multipole contributions to collective excitations in fullerenes, Phys. Rev. A 92, 021403 (2015)
  M. Schüler, J. Berakdar and Y. Pavlyukh
  
• Single or double electron emission within the Keldysh nonequilibrium Green’s function and Feshbach projection operator techniques, Phys. Rev. B 91, 155116 (2015)
  Y. Pavlyukh, M. Schüler and J. Berakdar
  
• Electron pair escape from fullerene cage via collective modes, Scientific Reports 6, 24396 (2016)
  M. Schüler, Y. Pavlyukh and J. Berakdar, P. Bolognesi and L. Avaldi
  
• Femtosecond dynamics of correlated many-body states in C fullerenes, New J. Phys. 18, 113055 (2016)
  S. Usenko, M. Schüler, A. Azima, M. Jakob, L. L. Lazzarino, Y. Pavlyukh, A. Przystawik, M. Drescher, T. Laarmann, J. Berakdar
  
• Second-order bosonic Kadanoff-Baym equations for plasmonaccompanied optical absorption, J. Phys.: Conf. Series 696, 12006 (2016)
  M. Schüler and Y. Pavlyukh
  
• Single and double photoemission and generalizations, J. Phys.: Conf. Series 696, 12005 (2016)
  Y. Pavlyukh
  
• Time-dependent many-body treatment of electronboson dynamics: Application to plasmon-accompanied photoemission, Phys. Rev. B. 93, 054303 (2016)
  M. Schüler, J. Berakdar and Y. Pavlyukh
  
• Vertex Corrections for Positive-Definite Spectral Functions of Simple Metals, Phys. Rev. Lett. 117, 206402 (2016)
  Y. Pavlyukh, A.-M. Uimonen, G. Stefanucci, R. van Leeuwen
  
• Padé resummation of many-body perturbation theories, Scientific Reports 7, 504 (2017)
  Y. Pavlyukh