Imaging of Cu(001) atoms by a new differential approach to photoelectron holography

We have applied a new differential method of photoelectron holography to bo th experimental and theoretical multiple-energy photoelectron diffraction d ata for Cu 3p bulk emission from Cu(001). Dominant forward-scattering effec ts contained in a normalized hologram chi (k) have been eliminated by takin g the k-difference delta chi (k) along each direction k. Two data sets that are different in k-space sampling ranges and densities have been analyzed to compare atomic images reconstructed from chi and delta chi In both cases , the original scheme has yielded only very weak images of back-scattering atoms and spurious features in the forward-scattering directions. On the ot her hand, the differential scheme has been found to be successful in suppre ssing the forward-scattering effects to image not only side-scattering and back-scattering atoms in either case, but also forward-scattering atoms in one of the two cases. (C) 2001 Elsevier Science BN; All rights reserved.