Point contact spin spectroscopy of ferromagnetic MnAs epitaxial films

被引:47
作者
Panguluri, RP [1 ]
Tsoi, G
Nadgorny, B
Chun, SH
Samarth, N
Mazin, II
机构
[1] Wayne State Univ, Dept Phys & Astron, Detroit, MI 48201 USA
[2] Penn State Univ, Dept Phys, University Pk, PA 16802 USA
[3] Penn State Univ, Inst Mat Res, University Pk, PA 16802 USA
[4] Sejong Univ, Dept Phys, Seoul 143747, South Korea
[5] USN, Res Lab, Washington, DC 20375 USA
关键词
D O I
10.1103/PhysRevB.68.201307
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We use point contact Andreev reflection spectroscopy to measure the transport spin polarization of MnAs epitaxial films grown on (001) GaAs. By analyzing both the temperature dependence of the contact resistance and the phonon spectra of lead, acquired simultaneously with the spin polarization measurements, we demonstrate that all the contacts are in the ballistic limit. A ballistic transport spin polarization of approximately 49% and 44% is obtained for the type A and type B orientations of MnAs, respectively. These measurements are consistent with our density functional calculations, and with recent observations of a large tunnel magnetoresistance in MnAs/AlAs/(Ga,Mn)As tunnel junctions.
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页数:4
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