Ultrafast Probing of Electron Localization by electron diffraction

Ultrafast Probing of Electron Localization by electron diffraction Reinhard Dörner University Frankfurt

Ultrafast Probing of Electron Localization by electron diffraction Reinhard Dörner University Frankfurt elocalized ld u o w e l o h hope in 20 fsec Synchrotron (ALS) 419 e. V

Ultrafast Probing of Electron Localization by electron diffraction Reinhard Dörner University Frankfurt Photo. Augerelectron diffraction Ion e. Ion localized ld u o w e l o h hope in 20 fsec Auger Electron (380 e. V) e

COLTRIMS: A “Cloud chamber” for Atomic Physics: Position sensitiv e multihit ion detector Electric field Time of Flight Times of flight & 2 dim positions 3 dim momentum vector Time of Flight Position sensitiv e multihit electron detector

COLTRIMS: A “Cloud chamber” for Atomic Physics: Position sensitiv e multihit ion detector Electric field Time of Flight B-field Times of flight & 2 dim positions 3 dim momentum vector Time of Flight Position sensitiv e multihit electron detector

10 e. V Photoelectron N+ 5 e. V N+ Auger Electron 380 e. V

N+ Photoelectron 0. 6 a. u. 100 a. u. 6 a. u. Auger Electron 100 a. u. N+ Markus Schöffler

COLTRIMS: A “Cloud chamber” for Atomic Physics:

K-hole localized right or left • K-Shell (n=1) < 10% of distance • Overlap: < 0. 01% K-hole delocalized gerade / ungerade orbital • Symmetry of the system

. . . and it is concluded that the hole state is localized on one of the two oxygen atom.

|left> 2 p N 2 |right> 3 su 1 pu vibrations 2 s 2 su 2 sg 1 s Experiments: Hergenhahn et al Ueda et al Becker et al 1 su 1 sg 100 me. V

Option 1: localized emission from left or right N 2

Option 1: localized emission from left or right Option 2: delocalized hole |g> = |left> + |right> |u> = |left> - |right>

He + 99 e. V -> He 1+(1 S) + e- Interference between different classical paths (diffraction pattern) Polarization O h C Photoelectron Diffraction

9 e. V K-Shell N 2 N+ N+ Jahnke et al, PRL 88(2002) 073002

delocalized emission from g or u localized emission from left or right N+ N+

delocalized emission from g or u localized emission from left or right Auger electron 5 fsec hole creation hole decay by Auger emission

RPA: N. Cherepkov, S. Semenov Coincidence Photo electron Auger electron 5 fsec hole creation hole decay by Auger emission

delocalized Photo localized electron Auger electron 5 fsec hole creation hole decay by Auger emission

photo electron 5 fsec Auger electron CO Science 320, 920 (2008);

Auger Electron Science 320, 920 (2008);

Auger photo 2 g - hole u - hole left - hole right - hole B. Mc. Curdy, T. Rescigno, N. Cherepkov, S. Semenov

“is” the photon Detection of the probe step linear or influences the result of the pump circular? “objective reality”

• incoherent • monochromatic light |left> 2 p N 2 |right> 3 su 1 pu coherent population of g and u 2 s 2 sg 1 s coherence is property of the system NOT of the excitation process 2 su 1 sg 100 me. V

EPR pair of electrons (|left> + |right>) = (|g> + |u>)

Ultrafast Probing of Localization of Electrons Entangled Electron Pairs Reinhard Dörner University Frankfurt

Experiment University Frankfurt: Markus Schöffler Till Jahnke Jasmin Titze Nadine Neumann Katharina Kreidi Achim Czasch Lothar Schmidt Sven Schössler Ottmar Jagutzki Horst Schmidt Böcking R. D. LBNL: Thorsten Weber Ali Belkacem Michael H. Prior Timur Osipov H. Adaniya Kansas State University C. Lewis Cocke Predrag Ranitovic Ali Alnaser Auburn University Allen Landers J. C. Thompson

Theory: LBNL: St. Petersburg Bill Mc. Curdy Tom Rescigno N. Cherepkov S. Semenov

Ultrafast Probing of Localization of Electrons Entangled Electron Pairs Reinhard. Dörner. University. Frankfurt