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

作者：Dargel P E^*; Honecker A; Peters R; Noack R M; Pruschke T

来源：Physical Review B, 2011, 83(16): 161104.

DOI：10.1103/PhysRevB.83.161104

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), have limited resolution (time-domain density-matrix renormalization group with Fourier transform method), or are limited to low-energy properties or single dominant modes (original continued fraction 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.

• 出版日期2011-4-22