Guerrero R, Aliev F G, Tserkovnyak Y, Santos T S, Moodera J S
Departamento de Fisica de la Materia Condensada, C-III, Universidad Autonoma de Madrid, 28049 Madrid, Spain.
Phys Rev Lett. 2006 Dec 31;97(26):266602. doi: 10.1103/PhysRevLett.97.266602. Epub 2006 Dec 28.
We report the experimental observation of sub-Poissonian shot noise in single magnetic tunnel junctions, indicating the importance of tunneling via impurity levels inside the tunnel barrier. For junctions with weak zero-bias anomaly in conductance, the Fano factor (normalized shot noise) depends on the magnetic configuration being enhanced for antiparallel alignment of the ferromagnetic electrodes. We propose a model of sequential tunneling through nonmagnetic and paramagnetic impurity levels inside the tunnel barrier to qualitatively explain the observations.
我们报告了在单个磁性隧道结中次泊松散粒噪声的实验观测结果，这表明通过隧道势垒内杂质能级进行隧穿的重要性。对于在电导中具有弱零偏异常的结，法诺因子（归一化散粒噪声）取决于铁磁电极反平行排列时增强的磁配置。我们提出了一个通过隧道势垒内非磁性和顺磁性杂质能级进行顺序隧穿的模型，以定性地解释这些观测结果。
