论文标题

投影密度矩阵嵌入理论的多碎片实时扩展:扩展系统中的非平衡电子动力学

A multi-fragment real-time extension of projected density matrix embedding theory: Non-equilibrium electron dynamics in extended systems

论文作者

Yehorova, Dariia, Kretchmer, Joshua S.

论文摘要

在这项工作中,我们得出了预计密度矩阵嵌入理论(PDMET)的多碎片实时扩展,该基质嵌入了,旨在处理强相关系统中的非平衡电子动力学。与先前开发的静态PDMET一样,实时PDMET分区将总系统分为许多片段。每个片段与系统的其余部分之间的耦合通过量子浴的紧凑表示。实时PDMET涉及同时传播每个单独的片段嵌入系统的波形以及总系统的辅助平均场波函数。运动方程是通过(i)在与每个单独片段相关的片段和浴室空间中的时间相关的schrodinger方程以及(ii)强制从片段中片段和平均值1-rdm获得的全局1粒子降低密度矩阵(1-rdm)之间的PDMET匹配条件的(II)。该方法的准确性是通过与时间依赖性密度 - 矩阵重质化组(TD-DMRG)和时间依赖性的Hartree-Fock(TDHF)理论进行比较来基准的。这些方法应用于具有有序且无序分布的杂质分布的单障碍安德森模型和多强度的安德森模型。结果表明,与TDHF相比有了很大的改善,并快速收敛到确切的动力学,碎片大小的增加。我们的结果表明,实时PDMET是一种模拟大尺寸异质系统中非平衡电子动力学的有前途且灵活的方法。

In this work, we derive a multi-fragment real-time extension of projected density matrix embedding theory (pDMET) designed to treat non-equilibrium electron dynamics in strongly correlated systems. As in the previously developed static pDMET, real-time pDMET partitions the total system into many fragments; the coupling between each fragment and the rest of the system is treated through a compact representation of the environment in terms of a quantum bath. Real-time pDMET involves simultaneously propagating the wavefunctions for each separate fragment-bath embedding system along with an auxiliary mean-field wavefunction of the total system. The equations of motion are derived by (i) projecting the time-dependent Schrodinger equation in the fragment and bath space associated with each separate fragment and by (ii) enforcing the pDMET matching conditions between the global 1-particle reduced density matrix (1-RDM) obtained from the fragment calculations and the mean-field 1-RDM at all points in time. The accuracy of the method is benchmarked through comparisons to the time-dependent density-matrix renormalization group (TD-DMRG) and time-dependent Hartree-Fock (TDHF) theory; the methods were applied to a single-impurity Anderson model and multi-impurity Anderson models with ordered and disordered distributions of the impurities. The results demonstrate a large improvement over TDHF and rapid convergence to the exact dynamics with an increase in fragment size. Our results demonstrate that real-time pDMET is a promising and flexible method to simulate non-equilibrium electron dynamics in heterogeneous systems of large size.

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