论文标题
自旋阀设备中自旋依赖性电子传输的动力平均场理论
Dynamical Mean-Field Theory for spin-dependent electron transport in spin-valve devices
论文作者
论文摘要
我们介绍了密度功能理论（DFT）和动态平均场理论（DMFT）的组合，用于通过两端纳米级设备计算电子传输。然后将该方法应用于呈现交替的CU和CO层的金属连接，它们表现出自旋依赖性电荷转运和巨型磁磁性（GMR）效应。计算表明，通过电子相关性，通过$ 3D $状态的连贯传输极大地抑制了。这主要是由于电子 - 电子相互作用引起的有限寿命，并且与计算的多体DMFT自我能源的假想部分直接相关。在费米的能量上，根据费米 - 液体行为，自我能源的假想部分消失了，驱动的抑制完全是由于电子相关性引起的能量谱的变化。基于我们的结果，我们最终建议，在CU/CO异质结构中测量的GMR在Fermi Energy上方约1 eV的电子中测量，这是动态相关效应的明显表现。
We present the combination of Density Functional Theory (DFT) and Dynamical Mean Field Theory (DMFT) for computing the electron transmission through two-terminals nanoscale devices. The method is then applied to metallic junctions presenting alternating Cu and Co layers, which exhibit spin-dependent charge transport and giant magnetoresistance (GMR) effect. The calculations show that the coherent transmission through the $3d$ states is greatly suppressed by electron correlations. This is mainly due to the finite lifetime induced by the electron-electron interaction and is directly related to the imaginary part of the computed many-body DMFT self-energy. At the Fermi energy, where in accordance with the Fermi-liquid behavior the imaginary part of the self-energy vanishes, the suppression of the transmission is entirely due to the shifts of the energy spectrum induced by electron correlations. Based our results, we finally suggest that the GMR measured in Cu/Co heterostructures for electrons with energies about 1 eV above the Fermi energy is a clear manifestation of dynamical correlation effects.
