Université de Fribourg

Multitier self-consistent $GW+\text{EDMFT}$

Nilsson, Fredrik ; Boehnke, Lewin ; Werner, Philipp ; Aryasetiawan, Ferdi

In: Physical Review Materials, 2017, vol. 1, no. 4, p. 043803

We discuss a parameter-free and computationally efficient ab initio simulation approach for moderately and strongly correlated materials, the multitier self-consistent GW+EDMFT method. This scheme treats different degrees of freedom, such as high- energy and low-energy bands, or local and nonlocal interactions, within appropriate levels of approximation, and provides a fully self-consistent...

Université de Fribourg

Nonequilibrium $GW+\mathrm{EDMFT}$: Antiscreening and Inverted Populations from Nonlocal Correlations

Golež, Denis ; Boehnke, Lewin ; Strand, Hugo U. R. ; Eckstein, Martin ; Werner, Philipp

In: Physical Review Letters, 2017, vol. 118, no. 24, p. 246402

We study the dynamics of screening in photodoped Mott insulators with long-ranged interactions using a nonequilibrium implementation of the GW plus extended dynamical mean-field theory formalism. Our study demonstrates that the complex interplay of the injected carriers with bosonic degrees of freedom (charge fluctuations) can result in long-lived transient states with properties that are...

Université de Fribourg

Influence of Fock exchange in combined many-body perturbation and dynamical mean field theory

Ayral, Thomas ; Biermann, Silke ; Werner, Philipp ; Boehnke, Lewin

In: Physical Review B, 2017, vol. 95, no. 24, p. 245130

In electronic systems with long-range Coulomb interaction, the nonlocal Fock- exchange term has a band-widening effect. While this effect is included in combined many-body perturbation theory and dynamical mean field theory (DMFT) schemes, it is not taken into account in standard extended DMFT (EDMFT) calculations. Here, we include this instantaneous term in both approaches and investigate its...

Université de Fribourg

When strong correlations become weak: Consistent merging of $GW$ and DMFT

Boehnke, Lewin ; Nilsson, Fredrik ; Aryasetiawan, Ferdi ; Werner, Philipp

In: Physical Review B, 2016, vol. 94, no. 20, p. 201106

The cubic perovskite SrVO3 is generally considered to be a prototype strongly correlated metal with a characteristic three-peak structure of the d-electron spectral function, featuring a renormalized quasiparticle band in between pronounced Hubbard sidebands. Here we show that this interpretation, which has been supported by numerous “ab initio” simulations, has to be reconsidered. Using...