Abstract
A quantum transport theory is developed for ferromagnetic semiconductor
nanostructures, where a ferromagnetic central region (FCR) is coupled to
non-magnetic leads. The strong spin-spin interaction between the charge
carriers and the localized magnetic electrons causes a large splitting
of the energy levels between the spin-up and spin-down carriers and
increases strongly the charge carrier scattering rate due to the spin
disorder scattering in the FCR. The electronic structure of the FCR and
the scattering rate can be estimated from the real and imaginary parts
of the poles of the retarded Green's function including the spin-spin
interaction. Then a quantum transport theory can be developed by using
the Keldysh non-equilibrium-Green-function technique. A general
expression for the transmission coefficient T(E) can be
calculated by using the retarded and advanced Green functions for the
FCR. Numerical results are presented for a ferromagnetic
AlAs/(Ga,Mn)As/AlAs quantum well with a single resonant level coupled to
the non-magnetic metallic leads by tunneling. The calculated results
show that the strong spin-spin interaction leads to a shift and a
broadening of the peak for T(E) as compared to the
non-interacting case. Also a double peak structure due to the splitting
of the resonant level is shown in the ferromagnetic temperature region.
Original language | English |
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Pages (from-to) | 80-84 |
Journal | Physica Scripta |
Volume | T114 |
DOIs | |
Publication status | Published - 2004 |
MoE publication type | A1 Journal article-refereed |