Abstract
The detailed nature of electronic states mediating ferromagnetic coupling in dilute magnetic semiconductors, specifically (Ga,Mn)As, has been an issue of long debate. Two confronting models have been discussed emphasizing host band versus impurity band carriers. Using angle resolved photoemission we show that the electronic structure of the (Ga,Mn)As system is significantly modified from that of GaAs throughout the valence band. Close to the Fermi energy, the presence of Mn induces a strong mixing of the bulk bands of GaAs, which results in the appearance of a highly dispersive band in the gap region of GaAs. For Mn concentrations above1%the band reaches the Fermi level, and can
thus host the delocalized holes needed for ferromagnetic coupling. Overall, our data provide a firm evidence of delocalized carriers belonging to the modified host valence band.
thus host the delocalized holes needed for ferromagnetic coupling. Overall, our data provide a firm evidence of delocalized carriers belonging to the modified host valence band.
Original language | English |
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Article number | 023006 |
Number of pages | 8 |
Journal | New Journal of Physics |
Volume | 19 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2017 Feb 2 |
Subject classification (UKÄ)
- Physical Sciences
Free keywords
- dilute magnetic semiconductors, band structure, magnetic coupling