论文标题
root-n-n Krylov空间校正向量，用于光谱函数，密度矩阵重新归一化组
Root-N Krylov-space correction-vectors for spectral functions with the density matrix renormalization group
论文作者
论文摘要
我们提出了一种基于修改的Krylov空间分解来计算校正媒介，我们提出了一种使用密度矩阵重新归一化组（DMRG）算法来计算通用汉密尔顿人的光谱函数的方法，该方法基于修改的Krylov空间分解来计算校正媒介。我们的方法需要使用Krylov空间分解来计算哈密顿传播器的根N（n = 2是标准平方根），并重复此过程n次以获得实际的校正量。我们表明，我们的方法极大地减轻了保持大型目标频率下的较大粘结尺寸的负担，这是常规校正-DMRG的一个问题，同时在大N上实现更好的计算性能。我们将我们的方法应用于T-J和Hubbard模型的旋转和电荷频谱功能，并在具有挑战性的两层级别的几何形状和跨越的方法中提供了一定的方法，并将其提供了一定的方法。
We propose a method to compute spectral functions of generic Hamiltonians using the density matrix renormalization group (DMRG) algorithm directly in the frequency domain, based on a modified Krylov space decomposition to compute the correction-vectors. Our approach entails the calculation of the root-N (N=2 is the standard square root) of the Hamiltonian propagator using Krylov space decomposition, and repeating this procedure N times to obtain the actual correction-vector. We show that our method greatly alleviates the burden of keeping a large bond dimension at large target frequencies, a problem found with conventional correction-vector DMRG, while achieving better computational performance at large N. We apply our method to spin and charge spectral functions of t-J and Hubbard models in the challenging two-leg ladder geometry, and provide evidence that the root-N approach reaches a much improved resolution compared to conventional correction-vector.
