Artículos de revistas
First principles study of the ferromagnetism in Ga1-xMnxAs semiconductors
Registro en:
Journal Of Physics-condensed Matter. Iop Publishing Ltd, v. 16, n. 46, n. 8243, n. 8250, 2004.
0953-8984
WOS:000225706000014
10.1088/0953-8954/16/46/011
Autor
da Silva, AJR
Fazzio, A
dos Santos, RR
Oliveira, LE
Institución
Resumen
We have performed ab initio calculations within the density-functional theory for Ga1-xMnxAs diluted semiconductors. Total energy results unambiguously show that a quasi-localized hole, with predominant p-like character, surrounds the fully polarized Mn up arrow d(5)-electrons. The calculations indicate that the holes form a relatively dispersionless impurity band, thus rendering effective-mass descriptions of hole states open to challenge. We obtain estimates both for the s = 1/2 hole and S = 5/2 Mn exchange coupling, and for the distance dependence of the effective Mn-Mn exchange interaction. The results demonstrate that the effective Mn-Mn coupling is always ferromagnetic, and thus non-RKKY, and is intermediated by the antiferromagnetic coupling of each Mn spin to the holes. 16 46 8243 8250