Departmento Fisica Materia Condensada, Universidad Autonoma de Madrid, 28049 Madrid, Spain.
Phys Rev Lett. 2012 Aug 10;109(6):066601. doi: 10.1103/PhysRevLett.109.066601.
We demonstrate that shot noise in Fe/MgO/Fe/MgO/Fe double-barrier magnetic tunnel junctions is determined by the relative magnetic configuration of the junction and also by the asymmetry of the barriers. The proposed theoretical model, based on sequential tunneling through the system and including spin relaxation, successfully accounts for the experimental observations for bias voltages below 0.5 V, where the influence of quantum well states is negligible. A weak enhancement of conductance and shot noise, observed at some voltages (especially above 0.5 V), indicates the formation of quantum well states in the middle magnetic layer. The observed results open up new perspectives for a reliable magnetic control of the most fundamental noise in spintronic structures.
我们证明了 Fe/MgO/Fe/MgO/Fe 双势垒磁隧道结中的散粒噪声取决于结的相对磁构型以及势垒的不对称性。所提出的理论模型基于通过系统的顺序隧道，并包括自旋弛豫，成功地解释了低于 0.5V 的偏置电压下的实验观察结果，其中量子阱态的影响可以忽略不计。在某些电压下（特别是在 0.5V 以上）观察到的电导和散粒噪声的微弱增强表明中间磁性层中形成了量子阱态。观察到的结果为在自旋电子结构中最基本的噪声的可靠磁控制开辟了新的视角。
