Theodonis Ioannis, Kioussis Nicholas, Kalitsov Alan, Chshiev Mairbek, Butler W H
Department of Physics, California State University, Northridge, California 91330-8268, USA.
Phys Rev Lett. 2006 Dec 8;97(23):237205. doi: 10.1103/PhysRevLett.97.237205.
We predict an anomalous bias dependence of the spin transfer torque parallel to the interface, Tparallel, in magnetic tunnel junctions, which can be selectively tuned by the exchange splitting. It may exhibit a sign reversal without a corresponding sign reversal of the bias or even a quadratic bias dependence. We demonstrate that the underlying mechanism is the interplay of spin currents for the ferromagnetic (antiferromagnetic) configurations, which vary linearly (quadratically) with bias, respectively, due to the symmetric (asymmetric) nature of the barrier. The spin transfer torque perpendicular to interface exhibits a quadratic bias dependence.
我们预测，在磁性隧道结中，与界面平行的自旋转移力矩Tparallel存在反常的偏置依赖性，其可通过交换分裂进行选择性调节。它可能会出现符号反转，而偏置并无相应的符号反转，甚至可能呈现二次方的偏置依赖性。我们证明，其潜在机制是铁磁（反铁磁）构型的自旋电流之间的相互作用，由于势垒的对称（非对称）性质，它们分别随偏置呈线性（二次方）变化。垂直于界面的自旋转移力矩呈现二次方的偏置依赖性。
