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arXiv 2010.08482cond-mat.str-el
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DMFT的加速杂质求解器及其图形扩展

Accelerated impurity solver for DMFT and its diagrammatic extensions

Corey Melnick, Patrick Sémon, Kwangmin Yu, Nicholas D'Imperio, André-Marie Tremblay, Gabriel Kotliar

摘要:

我们提出了ComCTQMC,GPU加速的量子杂质求解器。它使用连续时间量子蒙特卡罗(CTQMC)算法,其中的配分函数的杂交函数(CT-HYB)的方面进行扩展。ComCTQMC支持分区和蠕虫空间测量,它使用改进的估计和减少密度矩阵,以提高可观察的测量尽可能。ComCTQMC有效地测量所有的单粒子和双粒子格林函数,所有的静态观测值与当地的哈密顿量,以及每个杂质轨道的占用。ComCTQMC可以解决复杂的价值杂质与晶体场,是杂化的费米子和玻色子浴。最重要的是,当希尔伯特空间足够大时,ComCTQMC利用图形处理单元(GPU)(如果可用)来显著加速CTQMC算法。我们证明了加速超过600(100)的一个因素,在600 K的$δ$ -钚的模拟(无)晶场。在更简单的问题中,GPU提供的加速效果不太好,甚至会使CTQMC减速。在这里,我们描述的理论,算法和结构所使用的ComCTQMC,以实现这组功能和加速水平。

英文摘要:

We present ComCTQMC, a GPU accelerated quantum impurity solver. It uses the continuous-time quantum Monte Carlo (CTQMC) algorithm wherein the partition function is expanded in terms of the hybridisation function (CT-HYB). ComCTQMC supports both partition and worm-space measurements, and it uses improved estimators and the reduced density matrix to improve observable measurements whenever possible. ComCTQMC efficiently measures all one and two-particle Green's functions, all static observables which commute with the local Hamiltonian, and the occupation of each impurity orbital. ComCTQMC can solve complex-valued impurities with crystal fields that are hybridized to both fermionic and bosonic baths. Most importantly, ComCTQMC utilizes graphical processing units (GPUs), if available, to dramatically accelerate the CTQMC algorithm when the Hilbert space is sufficiently large. We demonstrate acceleration by a factor of over 600 (100) in a simulation of $δ$-Pu at 600 K with (without) crystal fields. In easier problems, the GPU offers less impressive acceleration or even decelerates the CTQMC. Here we describe the theory, algorithms, and structure used by ComCTQMC in order to achieve this set of features and level of acceleration.

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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