Adaptive Lanczos-vector method for dynamic properties within the density-matrix renormalization group
| Autor: | Dargel, P. E., Honecker, A., Peters, R., Noack, R. M., Pruschke, T. |
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| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 83 161104(R) (2011) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.83.161104 |
| Popis: | 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. Comment: 4 pages, 4 figures, accepted at Phys. Rev. B (RC) |
| Databáze: | arXiv |
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