含过渡金属分子器件中的单自旋负微分热电阻效应

Single-spin Negative Differential Thermoelectric Resistance Effects in Transition Metal-containing Molecular Devices

基于密度泛函理论和非平衡格林函数方法,研究了由锯齿型石墨烯纳米带(ZGNR)与含过渡金属(Tm)(=Cr,Mn,Fe和Ru)分子构成的器件的自旋过滤输运性质.研究结果表明单自旋的波函数失配使其在费米能级附近具有完美的自旋过滤特性,并在温度梯度下,由于费米能级附近的单自旋透射峰的Fano不对称性,导致含Ru的分子器件中的单自旋电流表现出明显的负微分热电阻效应(NDTR).

Based on the non-equilibrium Green’s function method combined with the density functional theory,we investigate the spin-resolved transport through transition metal(TM)(=Cr,Mn,Fe and Ru)-containing molecular devices in the presence of zigzag graphene nanoribbon(ZGNR)electrodes.The wave-function mismatch for the single-spin component results in a perfect spin-filtering property near the Fermi level.Moreover,we observe the Fano and Breit-Wigner resonant peaks in the transmission spectrum.Under a temperature gradient,the single-spin electric current exhibits a remarkable negative differential thermoelectric resistance(NDTR)in the Ru-complex molecular device,which originates from the Fano asymmetry of the single-spin transmission peak near Fermi level.