Low Temperature Physics: 33, 187 (2007); https://doi.org/10.1063/1.2409657 (5 pages)
Физика Низких Температур: Том 33, Выпуск 2-3 (Февраль 2007), c. 256-262    ( к оглавлению , назад )

Vertical spin transport in semiconductor heterostructures

P. Sankowski1, P. Kacman1, J.A. Majewski2, and T. Dietl1,2,3

1Institute of Physics, Polish Academy of Sciences, 32/46 al. Lotnikow, Warszawa 02668, Poland

2Institute of Theoretical Physics, Warsaw University, 69 ul. Hoza, Warszawa 00681, Poland
E-mail: jacek.majewski@fuw.edu.pl

3ERATO Semiconductor Spintronics Project

Received September 22, 2006


The Landauer—Büttiker formalism combined with the tight-binding transfer matrix method is employed to model vertical coherent spin transport within magnetization modulated semiconductor heterostructures based on GaAs. This formalism provides excellent physical description of recent experiments concerning the high tunneling magnetoresistance (TMR) in (Ga,Mn)As-based trilayers and highly polarized spin injection in p-(Ga,Mn)As/n-GaAs Zener diode. For both the TMR and the Zener spin current polarization, the calculated values compare well with those observed in the experiments and the formalism reproduces the strong decrease of the observed effects with external bias. We ascribe this decrease to the band structure effects. The role played in the spin dependent tunneling by carrier concentration and magnetic ion content is also studied.

PACS: 75.50.Pp Magnetic semiconductors;
PACS: 72.25.Hg Electrical injection of spin polarized carriers;
PACS: 73.40.Gk Tunneling.

Ключевые слова: ferromagnetic semiconductors, spin transport, tunneling magnetoresistance.