Department of Physics, Budapest University of Technology, Budapest, Hungary.
Phys Rev Lett. 2011 Dec 30;107(27):276801. doi: 10.1103/PhysRevLett.107.276801. Epub 2011 Dec 28.
We demonstrate a self-contained methodology for predicting conductance histograms of atomic and molecular junctions. Fast classical molecular-dynamics simulations are combined with accurate density functional theory calculations predicting both quantum transport properties and molecular-dynamics force field parameters. The methodology is confronted with experiments on atomic-sized indium nanojunctions. Beside conductance histograms the distribution of individual channel transmission eigenvalues is also determined by fitting the superconducting subgap features in the I-V curves. The remarkable agreement in the evolution of the channel transmissions demonstrates that the simulated ruptures are able to reproduce a realistic statistical ensemble of contact configurations, whereas simulations on selected ideal geometries show strong deviations from the experimental observations.
我们展示了一种用于预测原子和分子结电导谱的自洽方法。快速经典分子动力学模拟与准确的密度泛函理论计算相结合，可同时预测量子输运性质和分子动力学力场参数。该方法与原子级铟纳结的实验进行了对比。除了电导谱之外，还通过拟合 I-V 曲线中的超导能隙特征来确定各个通道传输本征值的分布。通道传输的显著一致性表明，模拟的断裂能够再现真实的接触构型统计集合，而在选定的理想几何结构上的模拟则与实验观察结果存在较大偏差。
