Adaptive Lanczos-vector method for dynamic properties within the density-matrix renormalization group

Abstract

Current widely-used approaches to calculate spectral functions using the density-matrix renormalization group in frequency space either necessarily include an artificial broadening (correction-vector method) or have limited resolution (time-domain density-matrix renormalization group with Fourier transform method). Here we propose an adaptive Lanczos-vector method to calculate the coefficients of a continued fraction expansion of the spectral function iteratively. We show that one can obtain a very accurate representation of the spectral function very efficiently, and that one can also directly extract the spectral weights and poles for the discrete system. As a test case, we study spinless fermions in one dimension and compare our approach to the correction vector method.

4 pages, 4 figures, accepted at Phys. Rev. B (RC)

References in corpus (6)

• The density-matrix renormalization group in the age of matrix product states
• The Kernel Polynomial Method
• Spectral function of spinless fermions on a one-dimensional lattice
• Density-matrix renormalisation group approach to quantum impurity problems
• Spectral Densities from Dynamic Density-Matrix Renormalization
• Local Density of States for Individual Energy Levels in Finite Quantum Wires

Cited by in corpus (1)

• Chebyshev matrix product state approach for spectral functions