IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Magnetic Interfaces and Nanostructures Tuesday Sessions
       Session MI+EL-TuA

Paper MI+EL-TuA3
Spin Filtering and Tunneling Magnetoresistance in Double Barrier Magnetic Heterostructures

Tuesday, October 30, 2001, 2:40 pm, Room 110

Session: Spintronics II: Spin Injection & Transport
Presenter: A.G. Petukhov, South Dakota School of Mines and Technology
Authors: A.G. Petukhov, South Dakota School of Mines and Technology
D.O. Demchenko, South Dakota School of Mines and Technology
A.N. Chantis, South Dakota School of Mines and Technology
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We report the results of our theoretical studies of spin-dependent resonant tunneling of holes in GaMnAs-based double-barrier magnetic heterostructures. Our approach is based on the k.p Hamiltonian with exchange-field parameters obtained from first-principle calculations and on multi-band transfer matrix technique. Zeeman splittings of the light hole (LH1) and heavy hole (HH2) resonant peaks are the most striking features of the calculated I-V characteristics of the structures with magnetic emitters. This finding is in good agreement with experimental data by H. Ohno et al.@footnote 1@ The splittings of other resonant channels are smeared due to various bandstructure effects. The resonant tunneling through magnetic quantum wells in GaAs/AlAs/GaMnAs/AlAs/GaAs resonant tunneling diodes displays even more pronounced Zeeman splittings of the resonant channels. These splittings strongly depend on the orientation of the magnetization. The spin polarization of the transmitted current is also quite significant and can be controlled by an external bias. This spin-filtering effect also leads to tremendous enhancement of tunneling magnetoresistance at small biases. @FootnoteText@ @footnote 1@H. Ohno et al., Appl. Phys. Lett. 73, 363 (1998).