Integrated Systems Laboratory, ETH Zürich, 8092 Zürich, Switzerland.
CSCS Future Systems, ETH Zürich, 8093 Zürich, Switzerland.
J Chem Phys. 2017 Aug 21;147(7):074116. doi: 10.1063/1.4998421.
Massively parallel algorithms are presented in this paper to reduce the computational burden associated with quantum transport simulations from first-principles. The power of modern hybrid computer architectures is harvested in order to determine the open boundary conditions that connect the simulation domain with its environment and to solve the resulting Schrödinger equation. While the former operation takes the form of an eigenvalue problem that is solved by a contour integration technique on the available central processing units (CPUs), the latter can be cast into a linear system of equations that is simultaneously processed by SplitSolve, a two-step algorithm, on general-purpose graphics processing units (GPUs). A significant decrease of the computational time by up to two orders of magnitude is obtained as compared to standard solution methods.
本文提出了大规模并行算法，以减少从头算量子输运模拟中的计算负担。利用现代混合计算机体系结构的能力来确定连接模拟域与其环境的开边界条件，并解决由此产生的薛定谔方程。虽然前一个操作采用的是特征值问题，可通过在现有中央处理器 (CPU) 上使用轮廓积分技术来解决，但后者可以转化为一个线性方程组，通过两步算法 SplitSolve 在通用图形处理单元 (GPU) 上同时进行处理。与标准解法相比，计算时间可显著减少多达两个数量级。
