Resonant photoemission of Ga1-xMnxAs at the Mn L edge
PhysRevB_69_075202.pdf 122 KB
Shikin, Alexander M.
semiconductor epitaxial layers
molecular beam epitaxial growth
Ga1-xMnxAs, x = 0.043, has been grown ex situ on GaAs(100) by low-temperature molecular-beam epitaxy. On the reprepared p(1 x 1) surface, resonant photoemission of the valence band shows a 20-fold enhancement of the Mn 3d contribution at the L3 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 L3 on-resonance photoemission spectrum for model parameters Δ, Udd, and (pdσ) consistent with our previous work and shows the same spectral shape on and off resonance thus rendering resonant photoemission measured at the L3 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.
Physical Review B - Condensed Matter and Materials Physics
American Physical Society
Copyright (c) 2004 The American Physical Society.