Hattass, M., Jahnke, T., Schössler, S., Czasch, A., Schöffler, M., Schmidt, L. Ph. H., Ulrich, B., Jagutzki, O., Schumann, F. O., Winkler, C., Kirschner, J., Dörner, R., Schmidt-Böcking, H.
Dynamics of two-electron photoemission from Cu(111)
Physical Review B 77, (16),pp 165432/1-9 (2008)
By using a new imaging technique for pairs of electrons emitted in coincidence from a surface, we investigated the two-electron photoemission from a Cu(111) surface in the energy range from (h/2π)ω=40 to 60 eV. The full solid angle coverage provides a comprehensive view into the details of the emission process and allows for a quantitative study of the exchange-correlation (XC) hole in the two-electron momentum final state. Evaluating the data in a center-of-mass frame the XC hole yields a value of ≈ 0.76 a.u. as smallest distance in momentum space. Additionally, we can demonstrate a significant dependency of the emission dynamics on the light polarization.