Abstract As the characteristic lengths of advanced electronic devices are approaching the atomic scale, ab initio simulation method, with full consideration of quantum mechanical effects, becomes essential to study the quantum transport phenomenon in them. The widely used non-equilibrium Green’s function (NEGF) combined with the density functional theory (DFT) approach prefers a localized basis set. As many states of the art DFT calculations for solid state systems are carried out in plane waves, it is thus worth to investigate the feasibility of using the plane wave basis set for large-scale quantum transport calculations. Here we present a plane wave method for large-scale transport calculations based on a previously developed scattering state calculation approach (Wang, 2005). We address the unique computational challenges of applying that approach for large-scale systems where it is too expensive to calculate all the occupied eigenstates of the system as in conventional DFT calculations. By applying several high-efficiency parallel algorithms, including linear-scaling DFT algorithm, folded spectrum method, and Chebyshev filter technique, we demonstrate that it is possible to use this approach to simulate a system with several thousand atoms on high performance computing platforms. This method is not only used to study nanowire interconnects, showing how the shape and point defect affects their transport properties, but also used to study nanoscale Si transistor. Such quantum transport simulation method will be useful for investigating and designing nanoscale devices.

中文翻译：

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在高性能计算平台上使用平面波基组进行大规模第一性原理量子输运模拟

摘要 随着先进电子器件的特征长度接近原子尺度，充分考虑量子力学效应的从头算模拟方法成为研究其中的量子输运现象必不可少的方法。广泛使用的非平衡格林函数 (NEGF) 与密度泛函理论 (DFT) 方法相结合，更喜欢局部基组。由于许多最先进的固态系统 DFT 计算是在平面波中进行的，因此值得研究使用平面波基组进行大规模量子传输计算的可行性。在这里，我们基于先前开发的散射状态计算方法（Wang，2005）提出了一种用于大规模传输计算的平面波方法。我们解决了将这种方法应用于大规模系统的独特计算挑战，在这些系统中，像传统 DFT 计算那样计算系统的所有占用特征态成本太高。通过应用几种高效并行算法，包括线性标度 DFT 算法、折叠谱法和切比雪夫滤波器技术，我们证明了使用这种方法在高性能计算平台上模拟具有数千个原子的系统是可能的。该方法不仅用于研究纳米线互连，显示形状和点缺陷如何影响其传输特性，还用于研究纳米级硅晶体管。这种量子传输模拟方法将有助于研究和设计纳米级器件。