TY  - JOUR
A1  - Rader, Oliver
A1  - Pampuch, Carsten
A1  - Shikin, A. M.
A1  - Gudat, Wolfgang
A1  - Okabayashi, J.
A1  - Mizokawa, T.
A1  - Fujimori, A.
A1  - Hayashi, T.
A1  - Tanaka, M.
A1  - Tanaka, A.
A1  - Kimura, A.
T1  - Resonant photoemission of Ga1-xMnxAs at the Mn L edge
N2  - Ga1-xMnxAs, x=0.043, has been grown ex situ on GaAs(100) by low-temperature molecular-beam epitaxy. On the reprepared p(1x1) surface, resonant photoemission of the valence band shows a 20-fold enhancement of the Mn 3d contribution at the L-3 edge. The difference spectrum is similar to our previously obtained resonant photoemission at the Mn M edge, in particular a strong satellite appears and no clear Fermi edge ruling out strong Mn 3d weight at the valence-band maximum. The x-ray absorption lineshape differs from previous publications. Our calculation based on a configuration-interaction cluster model reproduces the x-ray absorption and the L-3 on-resonance photoemission spectrum for model parameters Delta, U-dd, and (pdsigma) consistent with our previous work and shows the same spectral shape on and off resonance thus rendering resonant photoemission measured at the L-3 edge representative of the Mn 3d contribution. At the same time, the results are more bulk sensitive due to a probing depth about twice as large as for photoemission at the Mn M edge. The confirmation of our previous results obtained at the M edge calls recent photoemission results into question which report the absence of the satellite and good agreement with local-density theory
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Shikin, A. M.
A1  - Varykhalov, Andrei
A1  - Prudnikova, G. V.
A1  - Adamchuk, V. K.
A1  - Gudat, Wolfgang
A1  - Rader, Oliver
T1  - Photoemission from stepped W(110) : Initial or final state effect?
N2  - The electronic structure of the (110)-oriented terraces of stepped W(331) and W(551) is compared to the one of flat W(110) using angle-resolved photoemission. We identify a surface-localized state which develops perpendicular to the steps into a repeated band structure with the periodicity of the step superlattices. It is shown that a final-state diffraction process rather than an initial-state superlattice effect is the origin of the observed behavior and why it does not affect the entire band structure
Y1  - 2004
SN  - 0031-9007
ER  - 
TY  - JOUR
A1  - Varykhalov, Andrei
A1  - Shikin, A. M.
A1  - Gudat, Wolfgang
A1  - Moras, P.
A1  - Grazioli, C.
A1  - Carbone, C.
A1  - Rader, Oliver
T1  - Probing the ground state electronic structure of a correlated electron system by quantum well states: Ag/ Ni(111)
N2  - The ground state electronic properties of the strongly correlated transition metal Ni are usually not accessible from the excitation spectra measured in photoelectron spectroscopy. We show that the bottom of the Ni d band along [111] can be probed through the energy dependence of the phase of quantum-well states in Ag/Ni(111). Our model description of the quantum-well energies measured by angle-resolved photoemission determines the bottom of the Lambda(1) d band of Ni as 2.6 eV, in full agreement with standard local density theory and at variance with the values of 1.7-1.8 eV from direct angle-resolved photoemission experiments of Ni
Y1  - 2005
SN  - 0031-9007
ER  -