Miao Guo-Xing, Müller Martina, Moodera Jagadeesh S
Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2009 Feb 20;102(7):076601. doi: 10.1103/PhysRevLett.102.076601. Epub 2009 Feb 17.
Spin filtering happens due to the discriminative tunneling probabilities for spin-up and spin-down electrons through a magnetic barrier and can result in highly spin polarized tunnel currents. Combining two such barriers in a tunnel junction thus leads to large magnetoresistance without the necessity of magnetic electrodes. We demonstrate the realization of such unconventional tunnel junctions using double EuS spin filter barriers with Al electrodes. The novel nonmonotonic and asymmetric bias behavior in magnetoresistance can be qualitatively modeled in the framework of WKB approximations.
自旋过滤是由于自旋向上和自旋向下的电子通过磁垒时具有不同的隧穿概率而发生的，并且会导致高度自旋极化的隧穿电流。因此，在隧道结中结合两个这样的势垒会导致大磁电阻，而无需磁性电极。我们展示了使用带有铝电极的双EuS自旋过滤势垒实现这种非常规隧道结。磁电阻中新颖的非单调和不对称偏置行为可以在WKB近似框架内进行定性建模。
