论文标题
可调型旋转和转运卟啉纳米替伯型杂种
Tunable spin and transport in porphyrin-graphene nanoribbon hybrids
论文作者
论文摘要
最近，卟啉单元已连接到石墨烯纳米纤维（POR-GNR）上，可实现多种可能的结构。在这里，我们报告了两种典型的，实验性可行的POR-GNR杂种的第一原理计算，其中一种显示了与设备中用作电极相关的小带隙。嵌入Fe原子中的卟啉会导致自旋偏振，并具有自旋基态$ s = 1 $。我们采用密度功能理论和非平衡绿色的功能传输计算来检查2端的设置，涉及两个无金属的小带隙，POR-GNR电极之间的一个Fe-Por-GNR。 Fe-$ d $和GNR带状态之间的耦合在靠近费米能源的旋转运输中导致了Fano抗谐振功能。此功能使运输对FE旋转状态高度敏感。我们证明了FE上的机械应变或化学吸附如何使自旋分配到$ s = 1 $和$ s = 0 $，直接反映在转运的变化中。我们的理论结果为POR-GNRS杂种的表面合成提供了线索，该杂种可以为碳基旋转和化学传感打开新的途径。
Recently, porphyrin units have been attached to graphene nanoribbons (Por-GNR) enabling a multitude of possible structures. Here we report first principles calculations of two prototypical, experimentally feasible, Por-GNR hybrids, one of which displays a small band gap relevant for its use as electrode in a device. Embedding a Fe atom in the porphyrin causes spin polarization with a spin ground state $S=1$. We employ density functional theory and nonequilibrium Green's function transport calculations to examine a 2-terminal setup involving one Fe-Por-GNR between two metal-free, small band gap, Por-GNR electrodes. The coupling between the Fe-$d$ and GNR band states results in a Fano anti-resonance feature in the spin transport close to the Fermi energy. This feature makes transport highly sensitive to the Fe spin state. We demonstrate how mechanical strain or chemical adsorption on the Fe give rise to a spin-crossover to $S=1$ and $S=0$, respectively, directly reflected in a change in transport. Our theoretical results provide a clue for the on-surface synthesis of Por-GNRs hybrids, which can open a new avenue for carbon-based spintronics and chemical sensing.
