Bias dependence of spin injection into GaAs from Fe, FeCo, and (Ga,Mn)As contacts
نویسندگان
چکیده
Spin injection from Fe(001) and (Ga,Mn)As(001) into n-GaAs(001) was investigated using a method which provides two-dimensional cross-sectional images of the spin polarization in GaAs. While the distribution of the spin polarization below the injecting contact is nearly uniform for (Ga,Mn)As, a strong confinement near the contact edge is observed for Fe and FeCo. The spin polarization in GaAs changes sign when the injected current is reversed. Multiple sign reversals as a function of bias voltage as reported previously for Fe injectors are not observed with (Ga,Mn)As and Fe contacts grown on clean nþþ GaAs in agreement with earlier results for an epitaxial FeCo injector. VC 2011 American Institute of Physics. [doi:10.1063/1.3553932]
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