title: Fingerprints of Adiabatic versus Diabatic Vibronic Dynamics in the Asymmetry of Photoelectron Momentum Distributions.
abstract: When the Born-Oppenheimer approximation is valid, electrons adiabatically follow the nuclear motion in molecules. For strong nonadiabatic coupling between electronic states, one encounters a diabatic motion where the electrons remain local and do not adapt to molecular geometry changes. We show that the mentioned limiting cases are reflected differently in the asymmetry of time-resolved photoelectron momentum distributions. Whereas for adiabatic dynamics, the asymmetry directly maps the time-dependent average nuclear momentum, in the diabatic case, the asymmetry is determined by a nonclassical interference effect arising from the mixing of wave function components in different electronic states, which is present at times nonadiabatic transitions take place.
authors: Institut für Physikalische und Theoretische Chemie,  Universität Würzburg , Hubland Campus Nord, Emil-Fischer-Strasse 42, 97074 Würzburg, Germany.
authors: Mirjam
authors: M
authors: Falge
authors: Volker
authors: V
authors: Engel
authors: Stefanie
authors: S
authors: Gräfe
references: Annu Rev Phys Chem. 2002;53:41-65
references: 11972002
references: Annu Rev Phys Chem. 2005;56:25-56
references: 15796695
references: Chem Rev. 2004 Apr;104(4):1719-57
references: 15080710
references: J Chem Phys. 2011 May 14;134(18):184307
references: 21568506
references: Phys Rev Lett. 2010 Jun 11;104(23):233003
references: 20867233
references: Nature. 2004 Feb 26;427(6977):817-21
references: 14985755
references: Phys Chem Chem Phys. 2011 May 21;13(19):8681-9
references: 21290062
references: Annu Rev Phys Chem. 2003;54:89-119
references: 12524428
references: Annu Rev Phys Chem. 2012;63:325-52
references: 22475338
references: Science. 2006 Apr 14;312(5771):246-8
references: 16614216
references: J Chem Phys. 2004 Jan 1;120(1):158-64
references: 15267272
references: Phys Rev Lett. 2008 Sep 5;101(10):103001
references: 18851212