Dynamical density-matrix renormalization-group method
Dynamical density-matrix renormalization-group method
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DOI：
10.1103/physrevb.66.045114
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发表时间：
2002-07-15
影响因子：
3.7
通讯作者：
Jeckelmann, E
中科院分区：
文献类型：
--
作者：
Jeckelmann, E
提出了一种计算低维晶格量子多体系统动力学性质和激发态的密度矩阵重整化群（DMRG）方法。该方法基于动态相关函数及其贡献的激发态的精确变分原理。此动态 DMRG 是校正矢量 DMRG 的替代公式，但更简单且更准确。讨论了谱函数的有限尺寸标度，并描述了一种分析密集谱标度的方法。该方法的关键思想是依赖于尺寸的光谱展宽。动态 DMRG 和有限尺寸缩放分析在一维 Peierls-Hubbard 模型的光导率上得到了证明。与分析结果的比较表明，使用这些技术可以几乎精确地再现无限系统的谱函数。研究了 Mott-Peierls 绝缘体的光导率，结果表明其光谱与 Peierls（带）绝缘体和一维 Mott-Hubbard 绝缘体中观察到的简单光谱有质的不同。
A density-matrix renormalization-group (DMRG) method for calculating dynamical properties and excited states in low-dimensional lattice quantum many-body systems is presented. The method is based on an exact variational principle for dynamical correlation functions and the excited states contributing to them. This dynamical DMRG is an alternate formulation of the correction vector DMRG but is both simpler and more accurate. The finite-size scaling of spectral functions is discussed and a method for analyzing the scaling of dense spectra is described. The key idea of the method is a size-dependent broadening of the spectrum. The dynamical DMRG and the finite-size scaling analysis are demonstrated on the optical conductivity of the one-dimensional Peierls-Hubbard model. Comparisons with analytical results show that the spectral functions of infinite systems can be reproduced almost exactly with these techniques. The optical conductivity of the Mott-Peierls insulator is investigated and it is shown that its spectrum is qualitatively different from the simple spectra observed in Peierls (band) insulators and one-dimensional Mott-Hubbard insulators.