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最近实验表明,在室温下,锯齿边界石墨烯纳米带(z GNR)在长度1–16微米时测量到的电导率为G0/2=e2/h(Baringhaus等,2014).目前对这一单量子通道的电导尚未有比较好的物理解释.本文提出了用于解释z GNR单通道弹道输运性质的理论模型.该模型中,z GNR边界碳原子的sp3轨道杂化使边界原子的自旋轨道耦合作用增强,这一作用进一步增强了边界态的自旋翻转散射效应.当此效应足够大时,边界自旋态会成为自旋向上与自旋向下的叠加态.此时边界的耦合降低了边界自由度,导致z GNR的电导率下降为G0/2.
Recent experiments show that at room temperature, the z GNR has a conductivity of G0 / 2 = e2 / h measured at a length of 1 to 16 microns (Baringhaus et al., 2014) There is not a good physical explanation for the conductance of quantum channel. In this paper, a theoretical model for explaining the z GNR single-channel ballistic transport properties is presented. In this model, sp3 orbital hybridization of z GNR boundary carbon atoms causes the spins of the boundary atoms Orbital coupling enhances, which further enhances the spin-flip scattering effect of the boundary state. When the effect is large enough, the boundary spin state becomes the superposition state of spin-up and spin-down. Decreasing the boundary degrees of freedom leads to a decrease of the conductivity of z GNR to G0 / 2.