161 citations · 545 across the 17 of their papers we have counts for
15 papers · 1 filter
Aberration of the Green's function estimator in hybridization expansion continuous-time quantum Monte Carlo
Andreas Hausoel, Markus Wallerberger, Josef Kaufmann +2
We describe an aberration of the resampling estimator for the Green's function customarily used in hybridization expansion continuous-time quantum Monte Carlo. It occurs due to Pau…
Multi-band D-TRILEX approach to materials with strong electronic correlations
Matteo Vandelli, Josef Kaufmann, Mohammed El-Nabulsi +3
We present the multi-band dual triply irreducible local expansion (D-TRILEX) approach to interacting electronic systems and discuss its numerical implementation. This method is des…
Extended regime of coexisting metallic and insulating phases in a two-orbital electronic system
M. Vandelli, J. Kaufmann, V. Harkov +3
We investigate the metal-to-insulator phase transition driven by the density-density electronic interaction in the quarter-filled model on a cubic lattice with two orbitals split b…
Zoology of spin and orbital fluctuations in ultrathin oxide films
Matthias Pickem, Josef Kaufmann, Karsten Held +1
Many metallic transition-metal oxides turn insulating when grown as films that are only a few unit-cells thick. The microscopic origins of these thickness induced metal-to-insulato…
ana_cont: Python package for analytic continuation
Josef Kaufmann, Karsten Held
We present the Python package ana_cont for the analytic continuation of fermionic and bosonic many-body Green's functions by means of either the Pade approximants or the maximum en…
Comparing scattering rates from Boltzmann and dynamical mean-field theory
M. Wais, J. Kaufmann, M. Battiato +1
We compute scattering rates for electrons in the two-dimensional Hubbard model for a one-orbital metal and a two-orbital band insulator by means of the Boltzmann scattering equatio…
How correlations change the magnetic structure factor of the kagome Hubbard model
Josef Kaufmann, Klaus Steiner, Richard T. Scalettar +2
The kagome Hubbard model (KHM) is a paradigmatic example of a frustrated two-dimensional model. While its strongly correlated regime, described by a Heisenberg model, is of topical…
Self-consistent ladder DA approach
Josef Kaufmann, Christian Eckhardt, Matthias Pickem +3
We present and implement a self-consistent DA approach for multi-orbital models and ab initio materials calculations. It is applied to the one-band Hubbard model at various inte…
Statistical error estimates in dynamical mean-field theory and extensions thereof
Patrick Kappl, Markus Wallerberger, Josef Kaufmann +2
We employ the jackknife algorithm to analyze the propagation of the statistical quantum Monte Carlo error through the Bethe--Salpeter equation. This allows us to estimate the error…
Topotactic hydrogen in nickelate superconductors and akin infinite-layer oxides ABO2
Liang Si, Wen Xiao, Josef Kaufmann +4
Superconducting nickelates appear to be difficult to synthesize. Since the chemical reduction of ABO3 (A: rare earth; B transition metal) with CaH2 may result in both, ABO2 and ABO…
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…
The AbinitioDA Project v1.0: Non-local correlations beyond and susceptibilities within dynamical mean-field theory
Anna Galler, Patrik Thunström, Josef Kaufmann +3
The ab initio extension of the dynamical vertex approximation (DA) method allows for realistic materials calculations that include non-local correlations beyond and dynamic…
Towards ab initio calculations with the dynamical vertex approximation
A. Galler, J. Kaufmann, P. Gunacker +3
While key effects of the many-body problem---such as Kondo and Mott physics---can be understood in terms of on-site correlations, non-local fluctuations of charge, spin, and pairin…
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…