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Efficient DMFT-simulation of the Holstein-Hubbard Model

Philipp Werner·Andrew J. Millis
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Abstract

We present a method for solving impurity models with electron-phonon coupling, which treats the phonons efficiently and without approximations. The algorithm is applied to the Holstein-Hubbard model in the dynamical mean field approximation, where it allows access to strong interactions, very low temperatures and arbitrary fillings. We show that a renormalized Migdal-Eliashberg theory provides a reasonlable description of the phonon contribution to the electronic self energy in strongly doped systems, but fails if the quasiparticle energy becomes of order of the phonon frequency.

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Philipp Werner, Andrew J. Millis. 2007-10-04. Efficient DMFT-simulation of the Holstein-Hubbard Model. https://doi.org/10.1103/physrevlett.99.146404

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