Ozyilmaz B, Kent A D, Sun J Z, Rooks M J, Koch R H
Department of Physics, New York University, New York, New York 10003, USA.
Phys Rev Lett. 2004 Oct 22;93(17):176604. doi: 10.1103/PhysRevLett.93.176604.
Current-induced excitations in Cu/Co/Cu single ferromagnetic layer nanopillars ( approximately 50 nm in diameter) have been studied experimentally as a function of Co layer thickness at low temperatures for large applied fields perpendicular to the layers. For asymmetric junctions current-induced excitations are observed at high current densities for only one polarity of the current and are absent at the same current densities in symmetric junctions. These observations confirm recent predictions of spin-transfer torque induced spin-wave excitations in single layer junctions with a strong asymmetry in the spin accumulation in the leads.
在低温下，针对垂直于层的大外加磁场，研究了直径约50纳米的Cu/Co/Cu单铁磁层纳米柱中电流诱导的激发随Co层厚度的变化。对于不对称结，仅在一个电流极性下，在高电流密度时观察到电流诱导的激发，而在对称结中相同电流密度下则不存在这种激发。这些观察结果证实了最近关于在引线中自旋积累具有强烈不对称性的单层结中，自旋转移力矩诱导自旋波激发的预测。
