Orthogonal polynomial representation of imaginary-time Green’s functions

By Lewin Boehnke, Hartmut Hafermann, Michel Ferrero, F. Lechermann, Olivier Parcollet. 2011

145 citations recorded by the source corpus.

We study the expansion of single-particle and two-particle imaginary-time Matsubara Green's functions of quantum impurity models in the basis of Legendre orthogonal polynomials. We discuss various applications within the dynamical mean-field theory (DMFT) framework. The method provides a more compact representation of the Green's functions than standard Matsubara frequencies, and therefore significantly reduces the memory-storage size of these quantities. Moreover, it can be used as an efficient noise filter for various physical quantities within the continuous-time quantum Monte Carlo impurity solvers recently developed for DMFT and its extensions. In particular, we show how to use it for the computation of energies in the context of realistic DMFT calculations in combination with the local density approximation to the density functional theory (LDA+DMFT) and for the calculation of lattice susceptibilities from the local irreducible vertex function.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics

View Paper: https://www.semanticscholar.org/paper/f6116dff24bb560e0261385cf0fe5f9f549a49d0

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In Atomic and Molecular Physics, and Optics

In Condensed Matter Physics

Citations in the corpus

Diagrammatic routes to nonlocal correlations beyond dynamical mean field theory (2017, background): “Alternatively, correlation functions can be represented in a Legendre polynomial basis (Boehnke et al., 2011) to obtain a compact representation.”