Natural-orbital impurity solver and projection approach for Green's functions
Lu Y, Cao X, Hansmann P, Haverkort MW (2019)
Publication Type: Journal article
Publication year: 2019
Journal
Book Volume: 100
Article Number: 115134
Journal Issue: 11
DOI: 10.1103/PhysRevB.100.115134
Abstract
We extend a previously proposed rotation and truncation scheme to optimize quantum Anderson impurity calculations with exact diagonalization [Y. Lu, M. Höppner, O. Gunnarsson, and M. W. Haverkort, Phys. Rev. B 90, 085102 (2014)PRBMDO1098-012110.1103/PhysRevB.90.085102] to density-matrix renormalization group (DMRG) calculations. The method reduces the solution of a full impurity problem with virtually unlimited bath sites to that of a small subsystem based on a natural impurity orbital basis set. The later is solved by DMRG in combination with a restricted-active-space truncation scheme. The method allows one to compute Green's functions directly on the real frequency or time axis. We critically test the convergence of the truncation scheme using a one-band Hubbard model solved in the dynamical mean-field theory. The projection is exact in the limit of both infinitely large and small Coulomb interactions. For all parameter ranges, the accuracy of the projected solution converges exponentially to the exact solution with increasing subsystem size.
Authors with CRIS profile
Involved external institutions
Max-Planck-Institut für Festkörperforschung
Germany (DE)
Ruprecht-Karls-Universität Heidelberg
Germany (DE)
Germany (DE)
Ruprecht-Karls-Universität Heidelberg
Germany (DE)
How to cite
APA:
Lu, Y., Cao, X., Hansmann, P., & Haverkort, M.W. (2019). Natural-orbital impurity solver and projection approach for Green's functions. Physical Review B, 100(11). https://doi.org/10.1103/PhysRevB.100.115134
MLA:
Lu, Y., et al. "Natural-orbital impurity solver and projection approach for Green's functions." Physical Review B 100.11 (2019).
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