Magnetic order and noncollinear spin transport of domain walls based on zigzag graphene nanoribbons
Magnetic order and noncollinear spin transport of domain walls based on zigzag graphene nanoribbons
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DOI：
10.1063/1.4982892
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发表时间：
2017-05
影响因子：
3.2
通讯作者：
Yihui Zhang;X. H. Yan;Yufeng Guo;Yang Xiao
中科院分区：
文献类型：
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作者：
Yihui Zhang;X. H. Yan;Yufeng Guo;Yang Xiao
考虑到奇异的自旋电子学性质，我们通过第一性原理计算提出了锯齿形石墨烯纳米颗粒（ZGNR）中可以形成畴壁（DW）的理论。基于密度泛函理论和非平衡态绿色函数的计算表明，ZGNR中可以存在突变型和螺旋型双稳态，这取决于实验中外加磁场所能实现的初始磁化条件.此外，由于DW的宽度小，因此优选螺旋DW。更重要的是，当两引线的磁化方向之间的相对夹角（θ）达到135°时，费米能级处的透射率几乎保持不变。这种特性表明，ZGNR基自旋电子器件的磁化方向的轻微变化不会改变电导。另一方面，由于DW的宽度较大，DW的磁化强度分布在小θ时是螺旋性质的，但随着θ的增加，DW的磁化强度分布将从螺旋性质转变为螺旋性质。考虑到奇异的自旋电子学性质，我们通过第一性原理计算提出了锯齿形石墨烯纳米颗粒（ZGNR）中可以形成畴壁（DWs）。基于密度泛函理论和非平衡态绿色函数的计算表明，ZGNR中可以存在突变型和螺旋型双稳态，这取决于实验中外加磁场所能实现的初始磁化条件.此外，由于DW的宽度小，因此优选螺旋DW。更重要的是，当两引线的磁化方向之间的相对夹角（θ）达到135°时，费米能级处的透射率几乎保持不变。这种特性表明，ZGNR基自旋电子器件的磁化方向的轻微变化不会改变电导。另一方面，当DW宽度较大时，DW的磁化强度分布在θ较小时呈螺旋状，但随着θ的增大，DW的磁化强度分布由螺旋状变为螺旋状。
Considering exotic spintronic properties, we propose by first-principles calculations that the domain walls (DWs) can form in zigzag graphene nanoribbon (ZGNR). The calculations based on the density functional theory and the non-equilibrium Green's function show that both abrupt and spiral DWs can exist in ZGNR depending on the initial magnetization conditions which can be implemented by the external magnetic field in experiments. Moreover, as the width of DW is small, a spiral DW is preferred. More importantly, the transmission at the Fermi level remains almost unchanged even when the relative angle (θ) between magnetization direction of two leads is up to 135°. Such a characteristic indicates that the slight change in the direction of magnetization of ZGNR-based spintronic devices will not alter the conductance. On the other hand, as the width of DW is large, the magnetization distribution of DW is of spiral nature at small θ, but it will change from the spiral-like to abrupt-like when θ increases.Considering exotic spintronic properties, we propose by first-principles calculations that the domain walls (DWs) can form in zigzag graphene nanoribbon (ZGNR). The calculations based on the density functional theory and the non-equilibrium Green's function show that both abrupt and spiral DWs can exist in ZGNR depending on the initial magnetization conditions which can be implemented by the external magnetic field in experiments. Moreover, as the width of DW is small, a spiral DW is preferred. More importantly, the transmission at the Fermi level remains almost unchanged even when the relative angle (θ) between magnetization direction of two leads is up to 135°. Such a characteristic indicates that the slight change in the direction of magnetization of ZGNR-based spintronic devices will not alter the conductance. On the other hand, as the width of DW is large, the magnetization distribution of DW is of spiral nature at small θ, but it will change from the spiral-like to abrupt-like when θ increases.