以脱氧核苷酸为研究对象,利用密度泛函的非平衡态格林函数方法,计算了电极距离对四种核苷酸分子电流的影响.计算结果表明:当用胞嘧啶通过硫原子修饰左侧电极时,分子电流的衰减曲线与实验结果在形状上保持一致.当电极距离增加到一定程度时,电流随电极距离的变化均可以通过相同的指数函数来表示.
Based on the density functional theory and the non-equilibrium Green function method, we calculated the effects of the distance between electrodes on the transverse transport properties of nucleotides. When the cytosine coupled to left electrode through thiol group, the numerical calculation result is well coincide with the experimental observations in shape. When the distance between electrodes increased to a certain extent, the decay of tunnel current with distance present a similar trend.