Half-metallic properties, single-spin negative differential resistance, and large single-spin Seebeck effects induced by chemical doping in zigzag-edged graphene nanoribbons
Half-metallic properties, single-spin negative differential resistance, and large single-spin Seebeck effects induced by chemical doping in zigzag-edged graphene nanoribbons
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锯齿形边缘石墨烯纳米带中化学掺杂引起的半金属特性、单自旋负微分电阻和大单自旋塞贝克效应
DOI：
10.1063/1.4904295
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发表时间：
2015
影响因子：
4.4
通讯作者：
Feng Jin-Fu
中科院分区：
文献类型：
--
作者：
Yang Xi-Feng;Zhou Wen-Qian;Hong Xue-Kun;Liu Yu-Shen;Wang Xue-Feng;Feng Jin-Fu
结合密度泛函理论和非平衡格林函数进行从头计算，研究具有铁磁态的锯齿形边缘石墨烯纳米带（ZGNR）中单个 B 原子或单个 N 原子掺杂剂对自旋相关输运特性和热旋转性能的影响。这些掺杂剂可以诱导费米能级附近的自旋向上（自旋向下）局域态，由于破坏性量子干涉效应，导致费米能级处具有 100% 负（正）自旋极化的半金属特性。此外，在这些掺杂的 ZGNR 中还观察到低偏置电压范围内的高自旋极化电流和高偏置电压范围内的单自旋负微分电阻。此外，B(N)掺杂ZGNR在费米能级附近同时实现了大的自旋向上（自旋向下）塞贝克系数和非常弱的自旋向下（自旋向上）塞贝克效应，这表明自旋塞贝克效应与相应的电荷塞贝克效应相当。
Ab initio calculations combining density-functional theory and nonequilibrium Green's function are performed to investigate the effects of either single B atom or single N atom dopant in zigzag-edged graphene nanoribbons (ZGNRs) with the ferromagnetic state on the spin-dependent transport properties and thermospin performances. A spin-up (spin-down) localized state near the Fermi level can be induced by these dopants, resulting in a half-metallic property with 100% negative (positive) spin polarization at the Fermi level due to the destructive quantum interference effects. In addition, the highly spin-polarized electric current in the low bias-voltage regime and single-spin negative differential resistance in the high bias-voltage regime are also observed in these doped ZGNRs. Moreover, the large spin-up (spin-down) Seebeck coefficient and the very weak spin-down (spin-up) Seebeck effect of the B(N)-doped ZGNRs near the Fermi level are simultaneously achieved, indicating that the spin Seebeck effect is comparable to the corresponding charge Seebeck effect.