463 citations · 3k across the 44 of their papers we have counts for
29 papers · 1 filter
Fermion-boson vertex within Dynamical Mean-Field Theory
Erik G. C. P. van Loon, Friedrich Krien, Hartmut Hafermann +2
In the study of strongly interacting systems, correlations on the two-particle level are receiving more and more attention. In this work, we study a particular two-particle correla…
Second-order dual fermion approach to the Mott transition in the two-dimensional Hubbard model
Erik G. C. P. van Loon, Mikhail I. Katsnelson, Hartmut Hafermann
We apply the dual fermion approach with a second-order approximation to the self-energy to the Mott transition in the two-dimensional Hubbard model. The approximation captures nonl…
Intersite electron correlations on inhomogeneous lattices: a real-space dual fermion approach
Nayuta Takemori, Akihisa Koga, Hartmut Hafermann
We develop a real-space extension of the dual fermion approach. This method is formulated in terms of real-space Green's functions and local vertex functions, which enables us to d…
Precursors of the insulating state in the square lattice Hubbard model
Erik G. C. P. van Loon, Hartmut Hafermann, Mikhail Katsnelson
We study the two-dimensional square lattice Hubbard model for small to moderate interaction strengths by means of the ladder dual fermion approach. The non-local…
Multiband Dual Fermion Approach to Quantum Criticality in the Hubbard Honeycomb Lattice
Daniel Hirschmeier, Hartmut Hafermann, Alexander I. Lichtenstein
We study the Hubbard model on the honeycomb lattice in the vicinity of the quantum critical point by means of a multiband formulation of the Dual Fermion approach. Beyond the stron…
Diagrammatic routes to nonlocal correlations beyond dynamical mean field theory
G. Rohringer, H. Hafermann, A. Toschi +6
Strong electronic correlations pose one of the biggest challenges to solid state theory. We review recently developed methods that address this problem by starting with the local,…