Electronic structure of (Ga,Mn)As revisited
Artikel i vetenskaplig tidskrift, 2017

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 above 1% 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.

magnetic coupling

dilute magnetic semiconductors

band structure

Författare

Janusz Kanski

Chalmers, Fysik

Lars Ilver

Chalmers, Fysik

K. Karlsson

Högskolan i Skövde

I. Ulfat

University of Karachi

M. Leandersson

Lunds universitet

J. Sadowski

Institute of Physics of the Polish Academy of Sciences

Lunds universitet

I. Di Marco

Uppsala universitet

New Journal of Physics

1367-2630 (ISSN)

Vol. 19 Article no. 023006 - 023006

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1088/1367-2630/aa5a42