162 citations · 645 across the 12 of their papers we have counts for
12 papers
Symmetric Improved Estimators for Continuous-time Quantum Monte Carlo
Josef Kaufmann, Patrik Gunacker, Alexander Kowalski +2
We derive equations of motion for Green's functions of the multi-orbital Anderson impurity model by differentiating symmetrically with respect to all time arguments. The resulting…
Collective Modes in Excitonic Magnets: Dynamical Mean-Field Study
D. Geffroy, J. Kaufmann, A. Hariki +3
We present a dynamical mean-field study of dynamical susceptibilities in two-band Hubbard model. Varying the model parameters we analyze the two-particle excitations in the normal…
State- and superstate-sampling in hybridization-expansion continuous-time quantum Monte Carlo
Alexander Kowalski, Andreas Hausoel, Markus Wallerberger +2
Due to the intrinsic complexity of the quantum many-body problem, quantum Monte Carlo algorithms and their corresponding Monte Carlo configurations can be defined in various ways.…
Impact of self-consistency in dual fermion calculations
Tin Ribic, Patrik Gunacker, Karsten Held
The dual fermion (DF) method allows for calculating corrections due to non-local correlations relative to an effective impurity model. Choosing the impurity as that of a dynamical…
w2dynamics: Local one- and two-particle quantities from dynamical mean field theory
Markus Wallerberger, Andreas Hausoel, Patrik Gunacker +5
We describe the hybridization-expansion continuous-time quantum Monte Carlo code package "w2dynamics", developed in Wien and Würzburg. We discuss the main features of this multi-or…
Divergences of the irreducible vertex functions in correlated metallic systems: Insights from the Anderson Impurity Model
P. Chalupa, P. Gunacker, T. Schäfer +2
In this work, we analyze in detail the occurrence of divergences in the irreducible vertex functions for one of the fundamental models of many-body physics: the Anderson impurity m…
Role of three-particle vertex within dual fermion calculations
T. Ribic, P. Gunacker, S. Iskakov +5
We investigate the influence of self-energy diagrams beyond the two-particle vertex level within dual fermion theory. Specifically, we calculate the local three-particle vertex and…
Continuous-time quantum Monte Carlo calculation of multi-orbital vertex asymptotics
Josef Kaufmann, Patrik Gunacker, Karsten Held
We derive the equations for calculating the high-frequency asymptotics of the local two-particle vertex function for a multi-orbital impurity model. These relate the asymptotics fo…
Mott-Hubbard transition in the mass-imbalanced Hubbard model
Marie-Therese Philipp, Markus Wallerberger, Patrik Gunacker +1
The mass-imbalanced Hubbard model represents a continuous evolution from the Hubbard to the Falicov-Kimball model. We employ dynamical mean field theory and study the paramagnetic…
Ab initio dynamical vertex approximation
Anna Galler, Patrik Thunström, Patrik Gunacker +2
Diagrammatic extensions of dynamical mean field theory (DMFT) such as the dynamical vertex approximation (DA) allow us to include non-local correlations beyond DMFT on all lengt…
Worm Improved Estimators in Continuous-time Quantum Monte Carlo
Patrik Gunacker, Markus Wallerberger, Tin Ribic +3
We derive the improved estimators for general interactions and employ these for the continuous-time quantum Monte Carlo method. Using a worm algorithm we show how measuring higher-…
Continuous-time Quantum Monte Carlo using Worm Sampling
Patrik Gunacker, Markus Wallerberger, Emanuel Gull +3
We present a worm sampling method for calculating one- and two-particle Green's functions using continuous-time quantum Monte Carlo simulations in the hybridization expansion (CT-H…