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arXiv 2004.10783cond-mat.mes-hallcond-mat.supr-con
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计算非均匀系统正常和反常时域平衡格林函数的有效数值方法

Efficient numerical method for evaluating normal and anomalous time-domain equilibrium Green's functions in inhomogeneous systems

Tomas Löthman, Christopher Triola, Jorge Cayao, Annica M. Black-Schaffer

摘要:

在这项工作中,我们开发了EPOCH:正交多项式CHain的平衡计算器,这是一种计算效率高的方法来计算与时间相关的平衡格林函数,包括超导体的反常格林函数,以捕获大型非均匀系统的时间演化。EPOCH方法推广了量子化学中的切比雪夫波包传播方法,并有效地结合了平衡量子凝聚态系统所需的费米-狄拉克统计。EPOCH的计算成本仅在系统自由度中线性缩放,从而也为非常大的系统生成极其有效的算法。我们通过计算二维和三维超导体-正常金属界面附近激发的时间演变,捕获透射以及正常和Andreev反射,展示了EPOCH方法的强大功能。

英文摘要:

In this work we develop EPOCH: Equilibrium Propagator by Orthogonal polynomial CHain, a computationally efficient method to calculate the time-dependent equilibrium Green's functions, including the anomalous Green's functions of superconductors, to capture the time-evolution in large inhomogeneous systems. The EPOCH method generalizes the Chebyshev wave-packet propagation method from quantum chemistry and efficiently incorporates the Fermi-Dirac statistics that is needed for equilibrium quantum condensed matter systems. The computational cost of EPOCH scales only linearly in the system degrees of freedom, generating an extremely efficient algorithm also for very large systems. We demonstrate the power of the EPOCH method by calculating the time-evolution of an excitation near a superconductor-normal metal interface in two and three dimensions, capturing transmission as well as normal and Andreev reflections.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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